Tax-Sensitive Portfolio Construction for Traders Using Automated Execution
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Tax-Sensitive Portfolio Construction for Traders Using Automated Execution

DDaniel Mercer
2026-05-31
25 min read

Build tax-aware trading bots with lot selection, wash-sale controls, batching, and reconciliation-ready reporting for stronger after-tax returns.

Tax-aware trading is not just an accounting exercise; it is a performance lever. For active investors, tax drag can quietly erase a meaningful share of gross returns, especially when strategies generate frequent realized gains, short holding periods, and repeated rebalancing. If you are using a trading bot or any automated execution stack, the question is not whether taxes matter, but how to design your system so that tax outcomes are managed deliberately rather than discovered later during filing.

This guide shows how to build a tax-sensitive workflow around portfolio tax optimization, tax lot selection, wash sale risk controls, and reporting automation. It is written for tax filers, crypto traders, and market participants who want their execution logic, bookkeeping, and reconciliation process to work together. That means thinking about trade batching, realized versus unrealized gains, inventory of lots, and the ability to produce records that are ready for a CPA, tax software, or your own end-of-year review. For a broader systems perspective on operational reliability, see our guide on making portable context safe across systems and the principles in privacy-first integration patterns.

1) Why Tax-Aware Automation Changes Portfolio Construction

Taxes are part of expected return, not a separate afterthought

Every automated strategy has an implicit tax profile. A momentum model that turns over positions weekly will usually realize more gains than a slow-moving allocation model, while mean-reversion systems may trigger more short-term offsets and more frequent lot decisions. If you ignore this tax profile, your backtest can look attractive in pre-tax terms while underperforming materially after taxes. The best practice is to model tax drag alongside slippage, fees, and spread costs, because all four affect the net value of the strategy.

This becomes especially important when you compare conventional equities against crypto. In equity accounts, you may have access to specific identification and lot-aware optimization; in crypto, tax rules vary by jurisdiction, but the recordkeeping burden is often heavier because each disposal can create a taxable event. Traders who want a deeper risk lens can borrow from hedging frameworks for investment risk and treat tax liability as another form of exposure that must be hedged or minimized through design.

Automation improves consistency, but it can also amplify mistakes

The same automation that removes emotion from trade execution can also execute the wrong trade at scale. If your bot rebalances into a loss position too aggressively, or repeatedly harvests losses without understanding replacement security restrictions, you can create avoidable compliance problems. A well-designed workflow should separate signal generation, tax screening, execution, and reporting so that a single model decision does not automatically become a taxable mistake. In practice, that often means building pre-trade checks and post-trade reconciliation into the same event pipeline.

For builders familiar with operations and tooling, this is similar to the difference between a good idea and a production system. The article on Linux-first procurement checklists is not about trading, but it illustrates the same discipline: define constraints, document dependencies, and validate everything before deployment. Traders should apply that mindset to tax logic, because execution errors are expensive and difficult to unwind once lots are locked in.

Tax efficiency should be measured at the strategy level

Portfolio tax optimization is best assessed at the portfolio level rather than one trade at a time. A single sale may look inefficient, but if it funds a broader rebalance into a higher-quality asset or realizes a loss that offsets earlier gains, the total after-tax result can still be favorable. This is why you should measure tax alpha, realized gain volatility, and holding-period distribution, not just trade win rate. Automated systems are uniquely well suited to this because they can evaluate dozens of candidate lots and select the one that best fits the tax objective in milliseconds.

Pro Tip: Treat taxes like transaction costs in your bot design. If your strategy cannot survive realistic tax assumptions in backtest, it is probably overfit to pre-tax performance.

2) The Core Building Blocks of Tax-Sensitive Portfolio Construction

Tax lot selection is the first design choice

Tax lot selection determines which shares or units are sold when you reduce or close a position. The choice can materially change realized gains, holding periods, and ultimately tax owed. In taxable accounts, many traders benefit from specific identification because it allows them to choose lots with the highest cost basis, the longest holding period, or the best wash-sale outcome depending on the objective. Automated execution makes this practical because software can track lots at the security level and route orders to the most efficient inventory.

However, good lot selection requires accurate data. If your platform imports fills late, mislabels transfer-in lots, or fails to account for corporate actions, the tax logic may select the wrong basis. This is why reconciliation-ready design matters from day one. Think of it the way developers think about observability: the code is only as reliable as the data flowing through it. For a related look at how automation can be used safely, see how professionals should handle AI-assisted workflows carefully and apply the same standard to tax-sensitive trade selection.

Realized gains and unrealized gains must be managed separately

Realized gains create immediate tax implications; unrealized gains do not. That sounds obvious, but many bots optimize the wrong thing because they chase mark-to-market performance while ignoring the tax consequences of constantly realizing profits. A sound architecture keeps a separate view of realized and unrealized P&L, with thresholds for when to harvest gains, lock losses, or defer realization. In volatile markets, the difference between these two buckets can determine whether a strategy compounds efficiently or gets drained by short-term taxation.

For traders, unrealized gains also create sequencing risk. If you hold a large appreciated position and then need to rebalance, the timing of execution can decide whether the gain remains deferred or becomes taxable now. Automated systems can reduce this risk by continuously tracking exposure bands and deferring sales until they meet both risk and tax criteria. If you want to compare this kind of control logic with other data-driven decision systems, our article on AI-powered scouting using small-signal data shows how signal quality improves when the system tracks more than just surface-level outcomes.

Wash-sale logic must be embedded into the workflow

Wash sale considerations are among the most common sources of tax pain for active traders. In broad terms, if you sell a security at a loss and repurchase the same or substantially identical security within the wash-sale window, the loss may be disallowed and added to the cost basis of the replacement position. Automated systems that harvest losses without a wash-sale screen can accidentally neutralize the benefit they were trying to create. This is especially risky when multiple accounts, human traders, and bot-driven accounts all trade related instruments.

Because wash-sale rules can be nuanced and jurisdiction-dependent, the safest operational design is conservative: maintain a replacement-security mapping, apply account-level restrictions, and log every candidate loss harvest with an explanation of why it was or was not executed. That logging step matters for later reconciliation. For teams that value process safety and governance, the approach resembles the controls discussed in hardening dashboard access against unauthenticated flaws: assume edge cases will happen and design controls to catch them early.

3) How to Build a Tax-Aware Automated Trading Workflow

Start with a portfolio policy statement

Your automation should not begin with order routing. It should begin with a written policy that defines your tax objectives, holding-period preferences, tolerance for short-term gains, and rules for harvesting losses. Without this policy, each strategy maker or bot update will make ad hoc decisions that are difficult to audit later. A policy statement also reduces the temptation to overtrade because it establishes when a trade is justified by risk management versus when it is merely creating tax friction.

A strong policy should specify whether the account is taxable, retirement, or a hybrid structure; whether lot identification is allowed; and how often tax decisions are refreshed. For many traders, a monthly or weekly review is enough, while high-turnover strategies may need daily checks. The process discipline is similar to the planning found in corporate prompt literacy programs: if the decision environment is complex, you need standardized inputs and guardrails to keep outputs consistent.

Implement pre-trade tax checks in the execution layer

The execution engine should evaluate tax consequences before an order is sent. For example, if the bot is about to sell a lot at a gain, it should compare alternative lots, expected holding period, and portfolio risk impact. If the signal is a loss harvest, the engine should verify replacement restrictions, portfolio concentration limits, and any threshold required before realizing the loss. This makes the bot less like a black box and more like a controlled decision engine.

Practically, this means a trade proposal object should include not only ticker, side, quantity, and urgency, but also tax lot candidates, estimated gain or loss, expected holding period, and a wash-sale flag. If those fields are missing, the order should not be routed blindly. This style of robust workflow mirrors the safety logic in enterprise context portability patterns, where data is preserved, validated, and handed off without corruption.

Separate signal timing from tax timing when possible

Not every signal needs to be executed immediately. If a rebalance can occur on a scheduled batch basis without meaningfully increasing market risk, batching can improve after-tax outcomes by letting multiple trades offset each other. You may realize gains in one security while harvesting losses in another, reducing net taxable income while preserving the overall portfolio shape. The key is to quantify the cost of delay and compare it to the tax benefit of batching.

Some traders worry that batching reduces responsiveness. In practice, a well-designed scheduler can maintain urgency tiers: immediate execution for risk breaches, delayed execution for routine reweights, and end-of-day or week-end execution for tax-sensitive adjustments. This is comparable to the way media and content teams batch assets into campaign units, like the process described in repurposing event moments into content series. The principle is the same: group work when the value of coordination exceeds the value of instant action.

4) Trade Batching, Rebalancing, and Realized Gain Control

Use batch windows to reduce unnecessary realization

Batching trades gives you a chance to net winners against losers instead of realizing each move in isolation. For example, if a portfolio rule calls for reducing one tech position and adding to a defensive asset, batching both actions at the same time may allow the portfolio to absorb the tax cost more efficiently than executing them on different days. The trade-off is that batching introduces brief tracking error, so your scheduler must quantify whether the portfolio drift is acceptable.

In a taxable account, this often means designing specific windows such as “rebalance Friday at 3:30 p.m.,” with emergency override rules for risk events. That structure makes the portfolio easier to audit and easier to explain to a tax preparer. It also provides a stable record trail if regulators, auditors, or advisors need to review your process later. For a related example of structured timing and distribution, see how turning static product pages into stories improves conversion; here, timing and structure make decisions more coherent and defensible.

Prefer threshold-based sells over constant micro-rebalancing

Many bots rebalance too often because they react to every small deviation. That behavior is expensive in taxable accounts because each small sale can trigger a gain or loss event with real filing consequences. Threshold-based rebalancing solves this by only acting when the deviation becomes economically meaningful. In tax-sensitive portfolios, the threshold should account for both tracking error and the estimated tax cost of the trade.

A practical setup might use a drift band of 3% to 5% for large-cap equity sleeves and wider bands for volatile assets. The idea is to avoid overfitting the portfolio to tiny price movements that do not justify a taxable sale. This is similar to inventory management in volatile markets, where overreacting to each fluctuation can cause inefficiency. The article on stress-tested stock strategies for volatile conditions provides a useful analogy: buffer stock, buffer trades, and only move when the signal is strong enough.

Design sell sequencing around holding periods

Because short-term gains are often taxed less favorably than long-term gains, sell sequencing matters. If you have both short-term and long-term lots available, your bot may want to sell long-term lots first when the gain difference is small, or short-term loss lots first when harvesting losses. The exact priority depends on the trader’s tax rate, portfolio concentration risk, and replacement constraints. A rigid first-in, first-out process is rarely the best choice for a serious taxable account.

That said, prioritizing long-term lots should never override risk controls. If one lot is deeply appreciated and concentrated, or if a position is deteriorating fundamentally, tax deferral should not become a reason to hold too much risk. A strong execution system balances tax efficiency with portfolio health, just as agentic AI systems in finance must balance autonomy with oversight. Automation should assist judgment, not replace it.

5) Crypto Tax Considerations for Automated Traders

Crypto requires stricter reconciliation discipline

Crypto tax reporting is often more complex than equities because the ecosystem includes spot trades, swaps, staking, wrapped assets, transfers between wallets, and exchange-specific record formats. If a trading bot is active across multiple venues, the reconciliation burden can become significant very quickly. Traders should assume that every transfer, bridge, or conversion may need to be mapped properly for tax treatment and reporting. Missing basis data can create filing errors that are hard to clean up retroactively.

That is why crypto automation should include address labeling, exchange API logging, and exportable transaction histories from the beginning. Treat every wallet movement as an accounting event, not just a technical one. Risk-aware teams often benefit from the same skepticism used in tax scam prevention: if records do not line up cleanly, assume the process needs review before the filing deadline.

Wash-sale treatment may differ by asset class and jurisdiction

Crypto traders must be careful not to assume equity wash-sale logic applies identically in every jurisdiction. Rules can change, and some tax authorities have historically treated crypto differently from stocks or ETFs. Automated systems should therefore be configurable by market and by taxpayer location. The right design is not one global rule set, but a policy engine that can apply jurisdiction-aware constraints and preserve evidence for the chosen treatment.

From an operations standpoint, this means maintaining a rules table that maps asset class, venue, and jurisdiction to the applicable tax behavior. If you trade both stocks and digital assets, do not force a single generic loss-harvesting algorithm onto both. The compliance risk is too high. A useful parallel is the way teams evaluate legacy token risk in regulatory reassessments after SEC settlements: legal treatment can shift, so the system must be flexible enough to adapt.

Transfers, staking, and wrapped positions need clean event taxonomy

Crypto reports are only as good as the event taxonomy underneath them. A transfer between wallets should not be classified as a sale. A wrapped token conversion may have different tax implications than a normal trade. Staking rewards may be income rather than capital gains depending on rules and facts. Automated systems need event categories detailed enough to support tax preparation without manual guesswork.

For this reason, traders should choose software that separates trade events, income events, transfer events, and adjustment events. When those categories are mixed together, reconciliation becomes expensive and error-prone. The discipline is similar to the clarity required in privacy-first integration architectures, where each event type must be preserved with the right metadata.

6) Reporting Automation and Reconciliation-Ready Records

Build the report before tax season arrives

Waiting until tax filing season to reconstruct trading activity is a recipe for expensive cleanup work. Instead, your automation stack should generate periodic reports throughout the year: realized gains by account, open lot schedules, average holding periods, loss harvest logs, and unmatched transfer exceptions. This lets you catch issues while the year is still in progress, when the data is fresh and corrections are still possible. It also shortens the time your accountant spends interpreting your records.

A good reporting layer exports to CSV, PDF, and API formats so that it can feed tax software and internal review processes. It should also include reconciliation status, not just transaction lists. Think of it as the difference between a ledger and a dashboard. The dashboard helps you see whether the ledger is actually complete. For a broader lesson in documentation quality, see how to identify reliable service providers and avoid scams, which reinforces the same due-diligence mindset traders should apply to tax software vendors.

Reconciliation should compare broker, bot, and tax engine outputs

There are usually three sources of truth: the broker or exchange, the automated trading system, and the tax engine. Reconciliation means checking all three against one another and resolving mismatches. Common issues include partial fills that were not reflected in the bot, corporate actions that changed lot basis, or transfers that were recorded differently by two platforms. A robust reconciliation process flags these discrepancies automatically and requires human review before the annual report is finalized.

You can automate much of this with a simple cross-check table. For example, compare symbol, timestamp, quantity, execution price, fee, basis, and disposition type across all systems. If any field differs beyond a tolerance, the record moves to an exception queue. This is the same operational discipline seen in fields that rely on traceability, such as the review of altered records in data integrity workflows. In tax reporting, traceability is what keeps small errors from becoming audit headaches.

Use a reconciliation-ready data model

A reconciliation-ready data model should preserve raw fills, normalized trades, tax lots, corporate actions, transfer links, and account metadata. Avoid flattening everything into a single transaction table too early. Once context is lost, it is hard to reconstruct the basis chain later. The best systems retain both the original event and the derived tax view, so you can answer questions about how a number was generated, not just what the number is.

This design principle is especially important when multiple execution venues are involved. If a bot trades on an exchange, a brokerage account, and a wallet-connected venue, each source may export different fields or rounding behavior. Clean architecture reduces the chance that one venue’s quirks corrupt your tax file. That same concept underpins porting algorithms carefully across platforms: context preservation matters as much as the algorithm itself.

7) A Practical Comparison of Tax-Sensitive Execution Approaches

The table below compares common execution approaches for taxable traders. The point is not that one approach is always superior, but that each has a different tax footprint and operational burden. Automated traders should choose the model that matches their turnover, tax sensitivity, and reporting maturity. If you run multiple strategies, you may use more than one style inside the same portfolio.

Execution ApproachTax EfficiencyOperational ComplexityBest ForMain Risk
Immediate single-trade executionLow to mediumLowSimple, low-turnover strategiesUnnecessary realization and poor lot choice
Threshold-based rebalancingHighMediumTaxable portfolios with controlled drift bandsTemporary tracking error
Batch execution windowsHighMedium to highTraders who can tolerate scheduled delaysSignal staleness if markets move quickly
Loss-harvesting automationVery high when compliantHighPortfolios with frequent drawdowns or volatile lotsWash-sale errors and replacement mismatches
Fully rules-based tax lot optimizationVery highHighAdvanced traders and tax-sensitive systemsOverfitting to tax outcomes instead of investment goals

Notice that the most tax-efficient approach is not always the simplest or most robust. A strategy that saves taxes but introduces bad timing, excess turnover, or poor data integrity can still underperform after all costs are included. That is why the portfolio construction process must incorporate both tax and execution quality. For a broader example of balancing form and function, the piece on trade-offs in smartphone design offers a useful mental model: optimize for the actual use case, not for isolated features.

8) Implementation Checklist for Traders and Tax Filers

Pre-launch checklist for a tax-aware bot

Before you turn on automated execution, verify that your system can identify tax lots, estimate gains and losses, and tag every trade with a disposal reason. Confirm that it can distinguish between taxable sales, internal transfers, and non-taxable adjustments. Make sure the bot has account-level controls so it cannot create unintended tax consequences across multiple accounts. The most expensive mistakes usually happen when the strategy is technically successful but operationally blind.

Also confirm that the data pipeline is durable: fills, fees, rebates, and corporate actions should arrive reliably, and missing data should trigger alerts. If your execution stack resembles a general SaaS workflow, apply the same care you would to software buying decisions. A useful analogy is the evaluation process in hosting platform selection, where speed, compatibility, and uptime all matter at once. In tax automation, those dimensions become data quality, compatibility, and auditability.

Year-end checklist for reconciliation and filing

At year-end, generate an open-lots report, a realized gains summary, a loss-harvest log, and a transaction exception list. Review anything with missing cost basis, duplicate entries, or mismatched timestamps. If you use multiple exchanges or wallets, confirm that transfer chains reconcile end to end. The goal is to make your return preparation about review, not reconstruction.

If you are working with a CPA, provide both raw data and normalized reports. CPAs are faster and more accurate when they can inspect the source trail, especially for crypto tax reporting. Traders who prepare clean records typically spend less time answering follow-up questions and more time refining strategy. For a broader mindset on disciplined preparation, see how structured question frameworks improve outcomes; the same logic applies to choosing your tax workflow.

What to measure every month

Track realized gains, unrealized gains, turnover, average holding period, tax drag estimates, and unresolved reconciliation items every month. A monthly review lets you catch behavior drift before it becomes a filing problem. You should also monitor whether the bot is using the intended lot selection method, because silent configuration changes can alter tax outcomes without changing strategy performance metrics. If the strategy depends on harvesting losses, measure how often those trades were blocked by wash-sale constraints so you know whether the feature is actually delivering value.

For traders who want to tie process to real-world resilience, the importance of consistent performance habits is a reminder that disciplined routines matter. Tax-aware trading is not just about software; it is about operational habits repeated over time.

9) Common Mistakes That Destroy Tax Efficiency

Overtrading to improve backtest metrics

One of the biggest mistakes is optimizing for a prettier backtest rather than a better after-tax result. A high-turnover strategy can look sophisticated, but if it generates constant taxable events and weak net alpha, it may be inferior to a slower, more deliberate approach. Remember that every extra turnover cycle increases the probability of short-term realization and reporting complexity. The tax bill does not care that the signal looked elegant.

The same principle appears in platform-centered decision making: if you let the platform dictate the behavior instead of your goals, you lose autonomy. That is the insight behind preserving autonomy in platform-driven systems. Traders should preserve control over tax outcomes rather than surrendering them to default bot behavior.

Ignoring basis adjustments from fees and corporate actions

Fees, rebates, splits, mergers, and dividends can change effective basis and therefore alter taxable gain calculations. If your reporting tool does not model these events correctly, the resulting tax reports may be misleading even if the trades themselves were executed accurately. This is particularly important in portfolios with dividend reinvestment or frequent corporate actions. Basis accuracy is not optional; it is the foundation of trustworthy tax reporting.

To avoid this issue, reconcile against broker statements and corporate action notices, not just internal fill logs. In complicated accounts, manual review may still be required for edge cases. That level of care is consistent with the cautionary approach in regulatory risk reassessment for token projects: when the rules can change, documentation matters.

Mixing personal and strategy accounts

When personal and automated trades are mixed across the same instruments, tax optimization gets far more difficult. A trade in one account can create a wash-sale issue in another account, especially when related assets are involved. The safest route is to maintain strict account separation and inventory mapping. If you cannot separate them, you need stronger cross-account controls and better visibility across the entire household or entity structure.

That cross-account perspective is similar to the systems thinking in centralized asset management: once multiple assets live in different places, the challenge is to preserve visibility and control. The same is true for taxable trading systems.

10) Final Recommendations and Operating Model

Adopt a tax-first but risk-aware governance model

The best automated trading systems do not chase tax savings at the expense of the portfolio. They use tax logic to improve net returns while keeping risk controls intact. That means your bot should ask three questions before each execution: Is this trade needed for risk management? Is there a tax-efficient way to do it? Can the execution be delayed or batched without harming the portfolio? If the answer to any of these is unclear, the system should escalate rather than guess.

This governance model works because it preserves flexibility. Some trades deserve immediate execution, while others can wait for a better tax window. If you structure your workflow with clear policy, clean data, and exception handling, the tax function becomes a contributor to performance instead of an annual burden.

Build for auditability, not just convenience

Tax filers should assume they will need to explain their trades later. That means each automated decision should be traceable back to a signal, a rule, a lot selection choice, and an execution result. If your system can generate that chain automatically, you are far more likely to stay organized during tax season and far less likely to scramble for records. The strongest long-term advantage is not only lower tax drag, but also lower administrative friction.

One useful mindset is to treat every export as if it were destined for an auditor, CPA, or compliance review. If the records hold up under that standard, they will usually hold up under normal filing requirements too. That is the same standard of defensibility recommended in anti-scam tax controls and in any system where trust is earned through documentation.

Turn tax awareness into a repeatable edge

Traders who build tax sensitivity into their automation often discover a compounding advantage: fewer surprises, cleaner books, and more disciplined execution. The gains may not be visible in a single trade, but over a full year the reduction in tax drag and reconciliation overhead can be material. That is especially true for active traders and crypto participants who generate many taxable events. In those environments, process quality is performance.

If you want the portfolio to behave like a production system, then taxes must be part of the production design. Use lot-aware execution, wash-sale screening, batch windows, and reconciliation-ready reporting as default features, not optional add-ons. That is how a trading bot becomes a durable tool for tax filers rather than another source of year-end stress.

Pro Tip: The best tax-aware portfolios are designed to be boring at filing time. If your January is full of cleanup work, your automation is not finished.

Frequently Asked Questions

How does tax lot selection improve after-tax performance?

Tax lot selection lets you choose which units to sell, which can materially change the gain or loss recognized. In a taxable account, selling higher-basis lots can reduce gains, while selling specific loss lots can help offset other income or gains. Automated systems are especially useful because they can compare multiple lots instantly and apply the rule that best matches your policy.

What is the biggest wash-sale mistake traders make?

The most common mistake is harvesting a loss and then repurchasing the same or substantially identical asset too soon, often through another account or a different automation rule. Traders also forget related holdings, such as indirect replacements or similar exposure vehicles. A bot should screen for replacement risk before executing the loss harvest.

Should I prioritize realized gains or unrealized gains in my bot?

Both matter, but they serve different purposes. Unrealized gains are deferred and therefore tax-efficient until sold, while realized gains create immediate tax consequences. A good system preserves unrealized gains when possible, but it should still realize gains when needed for risk management, rebalancing, or strategy exit rules.

How often should I reconcile trading records for tax purposes?

Monthly reconciliation is ideal for most active traders, and weekly or daily checks may be necessary for high-volume bots or multi-venue crypto trading. Waiting until year-end increases the risk of missing basis adjustments, transfer issues, and classification errors. Frequent reconciliation keeps the filing process manageable.

What reports should a tax-aware trading system generate?

At minimum, generate realized gains reports, open-lot schedules, transaction histories, loss-harvest logs, wash-sale exception reports, and transfer reconciliation summaries. For crypto, include wallet and exchange movement logs with classification tags. These reports should be exportable in formats that your CPA or tax software can use directly.

Is crypto tax automation different from stock tax automation?

Yes. Crypto often involves more frequent transactions, more venue fragmentation, and more complex event classification. Transfers, staking, wrapping, and cross-chain activity add reporting complexity that many stock-only systems do not face. A crypto-capable bot should be built with stronger reconciliation and event taxonomy controls from the outset.

Related Topics

#taxes#portfolio-construction#compliance
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Daniel Mercer

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Senior editor and content strategist. Writing about technology, design, and the future of digital media. Follow along for deep dives into the industry's moving parts.

2026-05-14T07:26:08.865Z