Epoch time (also called Unix time or POSIX time) is a system for tracking time as a single number: the total seconds that have passed since January 1, 1970, 00:00:00 UTC (known as the Unix Epoch).
Think of Epoch time as an "absolute second counter" that computers use. Human-readable dates (like Sep 16, 2025, 01:36:46) are just translations of this number.
Epoch time — also called Unix Timestamp — represents time as the number of seconds (or milliseconds) that have elapsed since a fixed reference point:
January 1st, 1970 at 00:00:00 UTC
Instead of storing a date like “07 November 2024, 02:30 PM”, computers store:
1730970600 (seconds since 1970)
Human-readable dates are complicated — time zones, leap years, daylight savings, different calendar formats. Computers prefer a single increasing integer instead.
Epoch time commonly appears in two formats. Frontend frameworks (JavaScript) often use milliseconds; databases and APIs often use seconds.
Be sure to check which format your system uses to avoid conversion errors! Milliseconds are just seconds × 1000.
When you enter an Epoch timestamp, here’s what happens behind the scenes:
1730970600 seconds since 1970-01-01 00:00:00 UTC
= 2024-11-07 14:30:00 UTC
= 2024-11-07 09:30:00 EST (UTC-5)
Epoch timestamps are widely used across computing systems for consistent time representation:
Epoch time is a numeric representation of time (seconds since 1970-01-01 UTC), while DateTime is a human-readable format (e.g., 07 Nov 2024, 02:30 PM). Epoch is ideal for computations; DateTime is better for display.