A fundamental piece of any file management tool that has search capabilites is the ability to return results based on when a file was last changed. Unfortunatly this was not included in the first release of the File Manager Tool, but not to worry, it's the next thing on the road map that will be added to the search features.
It will be a simple addition to the search settings where you can choose a date with a date picker and also select an operator (<, =, >) for how the date will be searched. In addition to that there will be another date picker so you can select a date range to search beween. If an end date is set, the operator will be ignored.
I think that would cover the date filtering needs when searching for files.
Release will be pretty soon, but of course the application will tell you when the update is available.