I set up GIRO arrangment with IRAS (Personal and Property), MOE and UOB Card payment early last month and just saw the 1st IRAS deduction today. I guess I'll get the required 3 GIROs this month (IRAS x 2 and UOB Card) this month.
If your UOB card spending exceeds $500 for this calendar month (not statement month), then you'll still get the base interest 1.5% for your UOB ONE savings for August. Unless your funds are getting better than that elsewhere, then I would suggest transferring in the funds ASAP. Otherwise, you can transfer it in on 1st Sep to earn the base (1.5%) + bonus interest (1.85-3.88%) for next month.