How to minus 1 minute in a variable with format as '%Y-%m-%dT%H:%M:%S'

Question

I have a variable which holds the date & time as like = '2022-02-27T07:43:00'. (letter "T" is mandatory which is coming from my database by default. I still need that "T" in-between for all the variables). Now I need to minus 1 minute and assign that value to a new variable in the same format = '%Y-%m-%dT%H:%M:%S'.