OP needs to check with the IO he uses (as it may vary)if it's 3 calender months or 90 days for the money to be seasoned. (Tbh I've only seen 90 days in 'presence' terms)
It's a small difference but may be vital.
Maybe IO will let him make up his own calender that has 31 days in April 😮
But as others have said train wreck of a question.
Gomes As it is clearly written on the sheet you have just posted 30 day extension is at the 'discretion of the Immigration Officer.' You only have a definite answer once you apply.
But look at the other advice given already, that to mention your wife and child simply gives the IO an indication you are trying to game the Visa exempt scheme rather than apply for the correct visa.