dオプションが動作しません about instant HOT 2 CLOSED

Sorry for the wrong documentation, it's not supported. For the reason please read #2 .
Instead of using -d, you can run instant in conjunction with duration.

For example if you want to get unix time of 2020-08-11T00:00:00+09:00, run the command listed as bellow.

instant -f unix -a $(duration '2020-08-11T00:00:00+09:00')

The duration prints an ISO-8601 format string calculated with duration between now and input date time.(Duration requires fully ISO-8601 format date time and zone offset).

from instant.

Thank you for the solution.
I'll use duration expression instead.

from instant.