My DR Started Me On This Med Today After A

My DR started me on this med today after a pain Mangmnt Dr told me I could NOT continue taking my Xanax along with my MS Contin ER.& needed to STOP COLD TURKEY. My Dr said that was not right & we worked out a way to take the last refill I had & wean mysellf down from what I was taking & gave me a sertraline 50 mg to take 1 per day. What is best time to take this med .. At bed time or in the am??