Janet Jackson postponed her Sunday night concert at the Philips Arena in Atlanta after it was determined she had not yet fully recovered from a recent illness, it was announced late Saturday.

The concert has been rescheduled for Sunday, Oct. 19, according to a spokeswoman for tour organizer LiveNation. Tickets for Sunday’s performance will be honored on the new date.

On Monday night, the 42-year-old singer became ill for undisclosed reasons and was taken to Royal Victoria Hospital shortly before her scheduled concert in Montreal. She was released from the hosital two hours later.

Jackson’s subsequent “Rock Witchu Tour” shows in Boston on Wednesday, Philadelphia on Thursday and Greensboro, N.C., on Saturday were postponed.

“Janet was hoping to resume her tour in an effort not to disappoint her fans,” LiveNation said in a prepared statement Saturday night. “However, after arriving in Greensboro, it became evident that she is not fully recovered. A local doctor advised that she not perform tomorrow.”