Of course you can also use the datepicker menu with your mouse. You can choose between 4 different selection modes by clicking the 4 buttons at the top of the datepicker window.
To select a date just click the corresponding number, to select a whole month, simply click on the month name at the top.
The first one is “Change begin” – this way you can set the begin date of your timeframe. You may see that some dates are marked red and are unclickable. This means that they are beyond the end date of your timeframe.
To change your end date simply click the third button that says “Change end” which let’s you set the end date of the timeframe. You can see the selected dates being marked green in the calendar.
Another possibility to select a timeframe is the “Choose range” button. In this mode simply first click on the date you want to set as your start date and then the day you want to set as the end date. The area in between will be marked green automatically.
The last button “Shift” just shifts your timeframe along the calendar. This means that your timeframe stays the same length – your start date is just shifted to the date you click on.