Date comparison in Bash [duplicate]

Question

I need to compare two dates/times using Bash.

Input format: 2014-12-01T21:34:03+02:00

I want to convert this format to int and then compare the ints of the two dates.

Or does bash have another way to compare two dates?

Answer 1

You can compare lexicographically with the conditional construct [[ ]] in this way:

[[ "2014-12-01T21:34:03+02:00" < "2014-12-01T21:35:03+02:00" ]]

From the man:

[[ expression ]]
Return a status of 0 or 1 depending on the evaluation of the conditional expression expression.

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New update:

If you need to compare times with different time-zone, you can first convert those times in this way:

get_date() {
    date --utc --date="$1" +"%Y-%m-%d %H:%M:%S"
}

$ get_date "2014-12-01T14:00:00+00:00"
2014-12-01 14:00:00

$ get_date "2014-12-01T12:00:00-05:00"
2014-12-01 17:00:00

$ [[ $(get_date "2014-12-01T14:00:00+00:00") < $(get_date "2014-12-01T12:00:00-05:00") ]] && echo it works
it works