From ACal Wiki
As well as the obvious buttons in aCal, there are a variety of things that are not so obvious, most of which are available through a long press on something:
These are probably pretty obvious, but...
- Swipe left or right on the list of the day's events to move forward or backward a day.
- Swipe left or right on the month area to move forward or backward a month.
- Slide the year view up or down to move the view forward or backward.
- Press on month in the year view to go to that month in the month view. Note that the displayed day will not change.
- Press on a day in the month to see that day's events in the list below.
- Long press on an event in the day's list for Edit / Delete options.
- Long press on a collection in the collections list for Sync Now / Disable options.
- Long press on a server in the servers list for Export / Delete options.
- Long press on the year view to choose to go to a particular year.