In the Service Manager TSI, you may want to know, on a regular basis, which orders have to be carried out on a particular day.
Or in the Personnel Management TSI you may want to retrieve the visitors for the current week or day.
For this purpose you can use a selection by date field.
It would be convenient if you were able to save a recurring selection such as this one, but if you enter the date the 'usual' way, you will need to change it each time you want to apply the selection.

You can define a relative filter from the current date-time in the date-time field. Here, relative means with respect to the current date and time. The system date is used for determining the current date and time.

A relative selection on date-time may consist of a primary argument that defines the current date and time and a secondary argument that defines the period of the relative filter.

Secondary arguments are entered after the primary argument. The two arguments are separated by a space. The secondary argument is followed by a number that indicates the number of times the specified period should be applied (e.g. &D5, &D‑5). Both positive and negative numbers can be used. Note that a positive number is not indicated by a + sign.

Primary and secondary arguments are available in Planon ProCenter for date-time filter macros, check Primary and secondary arguments.