GNU date - parsing timezone with +HH:MM format

Question

I'm trying to parse a date that's extracted via exiftool from the metadata of MOV files. It comes in a format of e.g. 2024:05:31 20:57:23+03:00. Even though GNU's date has the %:z option, and it is able to produce a timestamp in such format, it's unable to parse existing value of it:

# echo $creation_date
2024:05:31 20:57:23+03:00

# date "+%Y:%m:%d %H:%M:%S%:z"
2024:06:08 22:04:15+02:00

# date "+%Y:%m:%d %H:%M:%S%:z" -d "$creation_date"
date: invalid date ‘2024:05:31 20:57:23+03:00’

What am I missing here?

Answer 1

Timezone is not a problem. Year-month-day is separated with :, which is unusual. They can be separated with - for date to understand them. See "DATE STRING" section in man date. You could change them:

creation_date='2024:05:31 20:57:23+03:00'
read -r ymd rest <<<"$creation_date"
date -d "${ymd//:/-} $rest"

Use strptime command from dateutils if you want to give exact format specification.