Some planners decide that the end time should be TBD (to-be-determined) at the shower. While this leaves the end of the party flexible, it also makes it harder to stay on schedule. Additionally, keep in mind that the expectant mother likely doesn't want to spend more than 3 hours or so with guests. If the shower runs too long, she'll feel obligated to stay but may not keep up the same energy that she had at the beginning of the shower.  While you can list the end time of the shower as TBD, it is better to have a set time that things are going to come to a close. This lets you set a schedule for each of the activities and have adequate time for the mother-to-be to socialize with everyone and hand out gift bags as they go. Additionally, having a set time stops the celebration from running too long and being draining.