SET (M) queries - Dates of Letters (employment, bank statements etc)

Hi everyone,

I am soon to apply for SET (M) when I reach within 28 days of qualifying 5 years. However, I have a few questions and there aren't many information provided on the main government website. This forum has been a massive help for me over the years and I hope someone can help me on here as there are so many changes this year!

Is the date of the application the date submitted online or the date attending in person to provide biometrics?

I briefly remember before when doing my applications that all letters from employer, banks statements must be within 30 days of application submission but I do not see any information on this now? I assume everything has to be dated within 30 days?

Thanks!