TennisRungs allow you the flexibility to set an OPEN date for a ladder as well as an END date.
By setting an OPEN date - it allows you to go ahead and setup your ladder early without players being allowed to make any challenges until the OPEN date has arrived. To set an open date, click on EDIT LADDER DETAILS from a ladder menu.
By setting an END date, this will prevent any challenges from being once this date is reached. You set the close date the same way, but just update the END Date field.
You can set and remove these dates at anytime.