Convert an ISO date to seconds since epoch in linux bash

Question

I have a date in the ISO format YYYY-MM-DDTHH:SS (e.g. 2014-02-14T12:30). I'd like to convert it in seconds since epoch using only the date command in linux bash.

All the dates refer to UTC locale.

I know that this question is easily eligible for duplicate... there are billions of questions about converting dates from one format to another but I can't find my particular scenario

thank you...

score 35 · Accepted Answer · edited Feb 17 '21 at 09:29

35

With GNU date (from the GNU coreutils package), specify the date to parse with -d and seconds since epoch with %s

$ date -d"2014-02-14T12:30" +%s
1392381000

Note that this will interpret the date to be parsed as being in your local time zone. If you want date to use a specific time zone, you must specify that, either via the variable TZ (which changes the default time zone for date), or in the date string. For UTC:

$ TZ=UTC date -d"2014-02-14T12:30" +%s
1392381000

or in the string, according to ISO 8601:

$ date -d"2014-02-14T12:30Z" +%s
1392381000

See ISO 8601 on Wikipedia for how to specify other time zones in the date string.

edited Feb 17 '21 at 09:29

sleske

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answered Feb 14 '14 at 11:41

kguest

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that's exactly what I tried... but it seems to report a wrong number if compared to the one given at http://www.epochconverter.com/. Can you explain to me what's going on? – Gianluca Ghettini Feb 14 '14 at 11:44
I mean, "date" output seems to be several hours late from the value given at www.epochconverter.com – Gianluca Ghettini Feb 14 '14 at 11:47
I tried the "-u" option but it seems not to work. "-u" means set/print UTC coordinates – Gianluca Ghettini Feb 14 '14 at 11:50
either as BMW suggests or include the timezone in the input to date, so $ date -d"2014-02-14T12:30 EDT" +%s – kguest Feb 14 '14 at 11:51
EDT option doesn't work. I have date from coreutils 8.4 (Centos 6.0) – Gianluca Ghettini Feb 14 '14 at 11:53
An alternative that might work: $ TZ='America/Los_Angeles' date -d"2014-02-14T12:30" +%s – kguest Feb 14 '14 at 12:02
Replace 'T' with whitespace. – Nehal J Wani Jul 17 '15 at 18:48
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This answer did not address timezones. I edited to add this - hope that's ok. – sleske Feb 17 '21 at 09:30

Mohammed Rafeeq · Answer 2 · 2018-07-02T09:22:39.640

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It is easier if you install gdate to deal with date strings that have timezones with nano second precision

install coreutils and you will get gdate along

on mac brew install coreutils

gdate --date="2010-10-02T09:35:58.203Z" +%s%N

This is particularly useful when inserting the time series value into influxdb

in a shell script variable = $(gdate --date="2010-10-02T09:35:58.203Z" +%s%N)

echo $variable

edited Jul 02 '18 at 09:22

answered Jun 27 '18 at 16:01

Mohammed Rafeeq

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Your answer seems to refer to a specific UNIX variant (MacOS X presumably). Please clarify what variant you are talking about - otherwise this answer is only confusing. For example, on Linux there is no "install" command, and on Debian there is a "coreutils" package, but it does not contain "gdate" (only "date"). – sleske Feb 17 '21 at 09:17
HI @sleske sorry i have moved away from the project and don't have the environmental information you have asked for – Mohammed Rafeeq Sep 10 '21 at 11:09

Convert an ISO date to seconds since epoch in linux bash

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