When to count 5 year ILR for T1 (G)

Does the 5 years for ILR count of the date of your first Tier 1 (G) application (as it does when it asks your age), or 5 years from the date they decided (minus 28 days of course)?

Thank you

5 years when they decided

More precisely, 5 years from the day you landed in UK...there are some allowances though

Thanks - I switched so was already in the UK.
So I guess the date of decision.

(only reason for asking is that they ask your age at date of application, so wondered if that was the benchmark)

Age points awarded at the date when you post your application but continuous residence period start when UKBA stamp the visa.

Thanks!