When you click Browse to select a timetable trigger in a simulation snapshot, a blank window opens although there many timetables defined in the project.
When you right-click the process and select Simulate, a window opens for you to select optional elements, such as timetables. From here, you select those elements if you plan to use them to configure your simulation.
Resolving the problem
Change the interval details by selecting Start time instead of Day of week. Then the Browse capability works when you set up a timetable trigger in a simulation snapshot.