Financial year — a reporting period for your company. You can choose whichever timeline suits you best and determine any day of the year to be your financial year end (FYE). It is common practice to choose the last day of the month as FYE, for example, March 31st.
Once you’ve chosen the date, you communicate FYE to IRAS as the deadlines for unaudited financial statements, annual reports, and tax filings depend on it. If you use outsourced accounting services for Singapore companies, you do not have to keep track of when the Financial Year ends — your service provider wil do that for you and prepare all the documents in accordance with the timeline.