From my experience it depends on the motion. When I filed for emergency custody of my son in Delaware, my ex-husband had a shorter time to file a response than when I was filing the regular motion for full custody. I think one was 2 weeks and the other was 30 days. Either way, it was stated in the motion, as @blueiiznh mentioned. Sometimes, I think you just show up to the proceeding and go from there, without having to file an actual response with the court first. If you need to know and are unsure, call the court house listed on the motion (assuming you’re the one that received something) and ask them.