monthly rules (left) and yearly rules (right)
If the template selected for the current DiaryGridLine was defined as a monthly or yearly template, then editing either of the begin/end rule properties brings up a property editor which allows you to select a Month and a Year Offset for monthlies.
For yearlies, only the year offset is necessary, the month is ignored for yearly diaries; only the Year Offset is taken into account.
Note that whether a monthly diary starts on the first of the month, or at the beginning of the week of the first of the month, is determined by the way you defined the structure of the scanned GridTemplate.
Topic 107071, last updated on 14-Apr-2022