Why is my Microsoft calendar missing events from a previous month?

1. Check the calendar parameters and make sure you have selected the right dates.
2. Look for the filter options if there are any, and make sure you have deselected them.
3. Check if the day views are expanded appropriately to include the month.
4. If that does not work, try switching to a different view, like Agenda, to see if any previous month’s events show up.
5. If it is still not possible to view events from a previous month, try resetting the calendar.