It takes around 30 minutes to an hour for sleeping pills or sleeping tablets to work and make you sleepy.
It's best to take the sleeping pills within 30 minutes to an hour before going to bed.
Make sure you have enough time to sleep at least 8 to 10 hours after taking the sleeping pills so that you won't be tired the next day.
It can take an hour or two for sleeping pills to wear off in the morning so you might feel a bit drowsy the next day after taking the sleeping pills.
For me when I take sleeping tablets I'm feeling drowsy within 30 minutes so I take the sleeping tablet within 30 minutes of going to bed.
But it can take different amount of times for different people.