Best Practice: Use a sandbox instance to try out calendar updates before changing the calendar you use in your live production instance. You can always export data first, then reimport after changing your calendar.
You can import a calendar using the update option after data has already been entered in your sheets to:
- Update its labels
- Add new strata
- Remove strata
When you add or remove time periods in a stratum where data already resides, the data may not stay in the same time period. Instead, the calendar might shift underneath it.
Here's what might happen if you add a time period where you already have data. You update your calendar to split 2015 into two halves. The new column slides the calendar over. Your data remains in the same relative position to 2015:
If you split an existing year, quarter, or month into separate parts, you need to decide how your existing values apply to the updated calendar. The system does not arbitrarily divide values you already saved.
For example, a calendar contains the years:
In sheets the data already exists for each year:
You update the calendar to split the year 2015 into halves; 1st Half 2015 and 2nd Half 2015. This adds another column to the sheets:
Data you entered in 2016 seems to shift to the 2nd Half of 2015. The data you entered in 2017 shifts to 2016.