This question already has an answer here:
My job requires me to work weekends, incuding saturday. I am vexed in my spirit to work on saturday the sacred day of our forefathers. I get off at 3:30pm. What should I do about this? Is it lawfull for me to continue the Sabbath after I get off work at 3:30? this just makes me grieved in the pit of my stomache.
So is it lawfull to take up sabbath after I get off work at 3:30 pm and pray for Hashem's forgiveness?