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. The epoch timestamp 0 can be written in ISO 8601 format as: 1970-01-01T00:00:00Z. One epoch hour is 3600 seconds, one epoch day is 86400 seconds long, leap seconds are not calculated. 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).

How to get the current epoch time in …

Perl time
PHP time()
Ruby Time.now (or Time.new). To display the epoch: Time.now.to_i
Python import time first, then time.time()
Java long epoch = System.currentTimeMillis()/1000;
Microsoft .NET C# epoch = (DateTime.Now.ToUniversalTime().Ticks - 621355968000000000) / 10000000;
VBScript/ASP DateDiff("s", "01/01/1970 00:00:00", Now())
MySQL SELECT unix_timestamp(now()) More information
PostgreSQL SELECT extract(epoch FROM now());
SQL Server SELECT DATEDIFF(s, '1970-01-01 00:00:00', GETUTCDATE())
JavaScript Math.round(new Date().getTime()/1000.0) getTime() returns time in milliseconds.
Unix/Linux date +%s
Other OS’s Command line: perl -e "print time" (If Perl is installed on your system)

2 Responses

  1. If only the real world were as simple as that


    • Thanks for shedding more light on the topic. Interesting link! The Java API documentation around currentTimeInMillis() also shares the same wisdom as yours.

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