Taking XL Concerta 36 mg in the morning. When is the best time to take sertraline?

Hi, MiriMiri!
It depends on your response to the medication:
"Very common (10% or more of users): Insomnia (up to 21%)
"Very common (10% or more of users): Somnolence (up to 13%)
It can go either way but more people experience insomnia than somnolence (sleepiness/drowsiness).
If it keeps you up at night you might want to take it in the morning. Your concerta should counteract any daytime sleepiness if you take it in the morning.
To be sure, I think you should ask your doctor for their advice.
Best regards,
Wildcat