This may give you some inspiration.
At the push of the button save the current date/time.
In a sensor calculate the number of days passed.
See Count days since last time?
and
Template to show days days / hours passed since switch on?
This may give you some inspiration.
At the push of the button save the current date/time.
In a sensor calculate the number of days passed.
See Count days since last time?
and
Template to show days days / hours passed since switch on?