Calculate the exact difference between two Unix timestamps, ISO 8601 dates, or human-readable date/time values. See results in days, hours, minutes, seconds, and milliseconds. Supports both 10-digit (seconds) and 13-digit (milliseconds) epoch timestamps. Perfect for debugging log files, measuring API response times, and calculating durations. All computation runs in your browser.
timestamp-diff.tool
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Days
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Hours
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Minutes
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Seconds
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Milliseconds
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Weeks
Frequently Asked Questions
How do I calculate the difference between two Unix timestamps?
Subtract one timestamp from the other to get the difference in seconds: diff = timestamp2 - timestamp1. Then convert: divide by 86,400 for days, 3,600 for hours, 60 for minutes. This tool does the conversion automatically and shows results in all units simultaneously.
What is a Unix epoch timestamp?
A Unix timestamp (POSIX time / epoch time) is the number of seconds elapsed since January 1, 1970 00:00:00 UTC. It's the universal standard for storing and comparing dates in programming. JavaScript uses millisecond timestamps (13 digits), while most Unix systems use seconds (10 digits). This tool auto-detects both formats.
What date formats are accepted?
This tool accepts: Unix timestamps in seconds (10 digits) or milliseconds (13 digits), ISO 8601 dates (2026-03-20T14:30:00Z), and common date strings (March 20, 2026, 2026/03/20). If a value looks like a number, it's treated as a timestamp; otherwise it's parsed as a date string.
Does this account for time zones?
Unix timestamps are always UTC-based, so timezone differences don't affect the calculation. When you enter human-readable dates, they're parsed in your browser's local timezone. For UTC-specific calculations, use ISO 8601 format with the Z suffix (e.g., 2026-03-20T09:00:00Z).
How accurate is this for very large time spans?
JavaScript's Date object is accurate to the millisecond for dates between approximately 271,821 BC and 275,760 AD. For practical purposes, this covers any realistic timestamp comparison. Note that "months" and "years" vary in length, so the tool shows exact units (days, hours, seconds) rather than approximate months.