Best way to shut down program after certain time

Question

I am working with a console application that scans multiple image directories and re-sizes then saves images if they exceed a certain size. Once a directory is finished processing a log is then pushed to a web-service page.

This utility program will be run at night for a given number of hours but must be shut down before normal office hours the following day, regardless of if it finished processing the current folder.

I am aware of 3 options to shut the program down:

1. Via Scheduled task setting "shut down after X hours": The concern I have with this option is that it might potentially close the program in the middle of the process, such as between saving the image and logging to the server.
2. After processing each image check the DateTime and if after certain time close it
3. User a Timer, set tick to a few hours, once tick handler is called then set a bool flag to false. After processing each image check the bool flag to see if it is time to shut the program down.

Does the timer option have a performance advantage over comparing DateTime?

Is there perhaps an even better way? Maybe I am missing something?

Answer 1

Checking the DateTime between processing seems like the best approach here.

Even if you use a Timer, you'll likely still want to check the current time when the timer event fires to make sure that it's time to exit. Just checking the time against a cutoff time seems like the simplest option all around.