Can I make a journal eg an expense accrual, dated March 31, that automatically reverses on April 1 without my having to make any entry myself.

Thanks for reaching out to us here in the Community, @paul32. 

Yes, you can create a journal entry for an accrual expense dated March 31. But there isn't an option to automatically reverse it on April 1 in the program. You'll need to manually reverse it by performing the steps below: 

1. Go to the Gear icon at the upper right. 
2. Select Chart of Accounts under Your Company. 
3. Find the appropriate account for the transaction.
4. Choose Run Report (View Register) from the Action column. 
5. Select the journal entry and click Edit.
6. In the transaction window, select Reverse.
7. Click Save. 

Once reversed, a new entry is created with the original Entry no. followed by an R. This is dated on the first day of the month following the original transaction and the original transaction's Debit and Credit amounts are reversed.

For more details, here's a great article you can refer to: Reverse A Journal Entry. 

This will get you in the right direction, @paul32. If you need anything else, please let me know. I'm always here to help.