What is epoch time? The Unix epoch (or Unix time or POSIX time or Unix timestamp) is the number of seconds that have elapsed since January 1, 1970 (midnight UTC/GMT), not counting leap seconds (in ISO 8601: 1970- 01-01T00:00:00Z). Literally speaking the epoch is Unix time 0 (midnight 1/1/1970), but 'epoch' is often used as a synonym for 'Unix time'. Many Unix systems store epoch dates as a signed 32-bit integer, which might cause problems on January 19, 2038 (known as the Year 2038 problem or Y2038). Human readable time Seconds 1 hour 1 day 1 week 1 month (30.44 days) 1 year (365.24 days) 3600 seconds 86400 seconds 604800 seconds 2629743 seconds 31556926 seconds