Changing the Length of Fiscal Periods (Accounting Periods)
For the purpose of filing GST/HST and QST returns, you can elect to have a fiscal year in which the quarters and months (fiscal periods) do not begin and end on the same dates as the calendar quarters and months. You can also apply for approval to extend or shorten fiscal months for a single fiscal year, otherwise than as provided for by law. To do so, file form FP-671-V, Notification of Fiscal Periods and Application for Approval to Extend or Shorten Fiscal Months.
As a rule, there cannot be more than four fiscal quarters in a fiscal year. The first fiscal quarter in a fiscal year begins on the first day of the fiscal year; the last fiscal quarter ends on the last day of the fiscal year. A fiscal quarter cannot be longer than 119 days and, except for the first and last quarters of the fiscal year, cannot be shorter than 84 days.
The first month in a fiscal quarter begins on the first day of the fiscal quarter; the last month ends on the last day of the last fiscal quarter. Fiscal months must be between 28 and 35 days long. Only the first and last fiscal months can be shorter than 28 days.