When starting using your account, you need to set up your Dates from

1. Settings 
2. Business settings
3. In the Financial Settings section, select Financial Settings (Fiscal Year & Accounting Method in the US) (From the menu More > Business Settings in Start version)

Year-End date and Lockdown date:

• Year-End date must always be the day before the beginning of the current year.
• You cannot edit, print, or create transactions before the Lockdown date.
• Year-End dates will need to be manually changed as you perform your Fiscal Year End procedures 
• The Year-End Lockdown date will not allow posting data prior to the date selected.

Accounts Start date:

• Account Start Date is optional, however, must be given if using opening balances, and will be the day after the Opening balances About opening balances in Accounting
• Accounts Start Date is the date of the first transaction posted, which can be retro dated.
• Accounts Start Date cannot be set before the current Year-End Lockdown date (although the lockdown date changes after closing the financial years).
• Account Start Date does not change year to year