Shell script - get current date with a fixed time element in ‘seconds since epoch’ format

Question

I’m fairly new to Linux and shell scripting so I hope that you will forgive a nooby question.

I want to get the current date but with a fixed time into a variable with the value in epoch seconds.

I have done this so far, but I’m really not happy with it:

startTime=$(date -d $(date +"%FT03:15:00") +%s)

It works ok but just seems a bit clunky (mainly because of the two calls to date) so was wondering if there is a better/cleaner way to achieve what I’m after?

I tried a printf alternative which cut down on one date call but...

The jobs that’s running this isn’t performance critical but I like to code for efficiency out of habit.

• Verpous: date is smart enough to understand that if you say 03:15:00 without specifying the full date, that means today. So date -d 03:15:00 +%s might be what you want
• Biggsy: Perfect! Works exactly how I wanted, is more concise and efficient. Many thanks
• David C. Rankin: FWIW, it's "newbie" (or just NB), not "nooby". Welcome to StackOverflow.