Select custom timeframe for Routes/Events/Trips

Hello,
Im running a Traccar server on a Synology DiskStation.

In the bottom Panel on the WebUI you can show events/routes from today, yesterday, last week etc.
Is it possible to customize this timeframe? For example If I want to see a specific day or not only last month but also the month before?

Sure, the source code is open. You can change anything you want.

Of course the code is open. But perhaps somewhere there is a function inside the GUI which I didn't saw.

But thanks for your very helpful answer :P