Simple way to convert HH:MM:SS (hours:minutes:seconds.split seconds) to seconds

Question

What\'s an easy way to convert 00:20:40.28 (HH:MM:SS) to seconds with a Bash script?

Split seconds can be cut out, it’s not essential.

Answer 1

TZ=utc date +'%s' -d "1970-01-01 00:00:38"