It is up to the company to decide its financial year end. Determining the optimum financial year end (FYE) may result in corporate tax exempts and other benefits. Every newly incorporated company must append a financial year end.
Suggested Readings
Do I have to comply with the Inland Revenue Authority of Singapore (IRAS)?
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Why and when should companies file the Estimated Chargeable Income (ECI)?
What are the advantages of setting a financial year end within 12 months of incorporation?