What exactly does START OF TODAY record?

[MikesClub]

I have a date field in my Users collection called “date joined”. It records when the user became a paying member of Mike’s Club. This date will be different from when the user initially created his/her profile.

I’ve set that field as an automatic field when the user creates their extended profile. But, the only custom formula options, under date & time, are “current time” and “start of today”.

I know I can extract the simple date from “current time”, but I’m curious: What exactly will “start of today” place in this field in my database? Will it be today’s date and 12:01 AM? Or some other format? I don’t think it matters, but I’d like to understand.

Second question (very important): Since this field is filled automatically, what happens if the user later edits his profile? Will the date update to the new current date? If so, is there any way to prevent that?

[MikesClub]

I know it’s just a minute after I posted the original question, but I think I answered part of it. I only included the automatic field in the “create profile” form. I did not include the field in the “edit profile” form, so that date will not be affected when the user edits his profile.

But the rest of my question still stands.

[njimmy10]

Well in a very simple words: start of today will get you the today’s date. example if you were storing it in a data and time field, you’ll get 28/2/2022 00:00. if in a date you’ll get 28/2/2022