python - How to change the date dynamically using a command in linux -

python - How to change the date dynamically using a command in linux -

i writing python code alter date in linux scheme today-1 (dynamically). tried various combinations but, yet not able succeed. searched , found close proximity scenario in question .

i able alter date if execute command static value say:

date --set="$(date +'2013%m%d %h:%m')"

however, don't want specify hardcoded value year i.e., 2013. instead want specify "%y-1" i.e.,

date --set="$(date +'%y-1%m%d %h:%m')"

if run above command next error

[root@ramesh ~]$ date --set="$(date +'%y-1%m%d %h:%m')" date: invalid date `14-11016 13:05'

thanks answer. did not seek approach though, reason beingness has 1 time 1 time again dealt formatting issues when working arithmetic operations incase if want to.

so, figured out much simpler , generalized approach

fetch previous_year value command

date --date='1 years ago'

this gives previous year date. can used in python programme update scheme in next way

"date --set=$(date +'%%y%%m%s %%h:%%m') % previous_year"

this method has few advantages like

i can apply method day , month "1 days ago", "1 month ago" along +%d, +%m, +%y values.

e.g., date --date='1 years ago' +%y

i don't have worry date , month arithmetic calculation logics

python linux datetime