Adds a day to a date. The value must be of the form {{Y,M,D},{H,I,S}}.
For example:
{{ value|add_day }}
When the value is {{2008,12,10},{15,30,0}}, the output is {{2008,12,11},{15,30,0}}.
The filter has an optional argument which defines the number of days to add:
{{ value|add_day:3 }}
When the value is {{2008,12,10},{15,30,0}}, the output is {{2008,12,13},{15,30,0}}.