Stopping the Trigger once condition is Fulfilled?

Hello all,

I have a scenario to run the process when the DB field is updated to a certain value. It is dependent on completion of jobs, the time for which is not fixed.

The design is such that there is a trigger which checks every 15 mins from 6PM to 9PM for that DB field.

Is there anyway I can stop the trigger once the value is updated for the that day?