Comments on: Convert date to days since 01-01-1970

By: John Gill

John Gill — Thu, 15 Apr 2010 10:39:13 +0000

Or you could use python:

>>> from datetime import date
>>> epoch = datetime.date(1970, 1, 1)
>>> expire = datetime.date(2011, 1, 1)
>>> (expire-epoch).days
14975

Zash — Wed, 14 Apr 2010 22:06:20 +0000

Which of course gives you something near the number of days since year 0, so if you substract the epoch year from %Y it should be closer-ish.

And things get offset by timezones, DST, leap seconds and such.

Zash — Wed, 14 Apr 2010 21:56:49 +0000

Oh, wait, no, but what about: date -d 2011-01-01 +scale=1\;365.2425\*%Y+%j|bc

Zash — Wed, 14 Apr 2010 21:54:00 +0000

Or, why not like this: date +%j\*%Y|bc

SWAT — Wed, 14 Apr 2010 21:52:41 +0000

That will also always round down the number Furthermore the version above nicely demonstrates the use of piping and quoting usage.

Zash — Wed, 14 Apr 2010 21:42:35 +0000

Or like this: echo $(($(date -d 2011-01-01 +%s) / 86400))