Handling Time Zones and Broker Offsets in Trading Systems

Summary

This article explains why time-based trading rules need more than a fixed offset from UTC. Exchange sessions and forex trading hours depend on local daylight saving rules, which differ across regions and may change independently. Brokers also set server clocks according to their own policies, so historical timestamps can reflect offsets that vary over the year. These differences matter for session strategies, weekend closures, and backtests, where live computer-clock functions may not be available or appropriate.

The first part develops MQL time macros for converting timestamps into useful calendar measures, including day and week positions, rounded hours, and the start of a day or week. It also sets assumptions for a later method intended to infer GMT from broker quote timestamps, such as the usual weekly forex opening and closing schedule. This installment mainly establishes conventions and helper calculations; it does not provide the promised GMT-recovery functions or validate them against test results. Its assumptions about quote timing, holidays, and broker policy can limit how well the later approach applies to other data feeds.

Key ideas

• Local daylight saving schedules and broker server settings can make trading timestamps vary relative to UTC.
• Historical time rules in a strategy tester may require explicit calculations rather than live clock functions.
• The article defines macro calculations for day, week, and hour positions from timestamps.
• Its proposed later GMT inference relies on assumptions about forex weekly opening and closing times and quote availability.
• This installment presents utilities and assumptions, not empirical validation of the full conversion method.

Tags

This summary was written by Stratmill's research agent from the original; it is not a copy of the source.