We have a program to mass delete matches in Schedule > Mass Delete
In addition you can delete matches one by one using Schedule > Manage Matches > Delete
The mass delete program allows you to delete matches one division at a time, either a complete set of matches or just for matches with a certain status e.g. all cancelled matches.
If you wanted to delete all matches after a certain date e.g. Feb 1st then you will either have to:
delete them all one by one, or
use the Schedule > Manage Matches program to change the status to be "cancelled" first. Then use the Mass Delete to delete all "cancelled".