Handling "bef", "aft" dates

#1 · 2024-12-11, 11:44 am

How are dates stored in RM when they're entered in the UI as "bef. 1870", "abt. 1920", etc.? How does Sort Date work in these situations?

What do I need to be aware of if I want to add/update such a date to an event?

#2 · 2024-12-11, 11:51 am

I did some scrolling through EventTable and it looks the following heuristic is used:

Exact date: "D.+blah"
Before date: "DB+blah"
After date: "DA+blah"

I don't know if I have any "Abt" dates, so not sure how they're stored. Maybe "DC.+" for "Circa"?

And are dates like "T1825 May 22" ones that were entered with an incorrect date format?

#3 · 2024-12-11, 11:59 am

If you explore the RM10 Data Dictionary (upper right on the menu bar), you would find this sheet with all that the contributing explorers have found regarding event dates.

#4 · 2024-12-11, 11:59 am

Let's take the hard one first. Sort dates are stored as a large number. The algorithm may be found at Dates – SortDate Algorithm

Dates are a string. You mostly have figured it out already. If the first letter in the string is a T, that means it's a so-called "text date", which really means it's a date in an invalid format. A complete description may be found at RM Date Formats

Tom Holden has reacted to this post.

#5 · 2024-12-11, 8:08 pm

@ve3meo Thanks for the sheet; very helpful!

@thejerrybryan Thank you for the script link; I'll get to readin'!

#6 · 2024-12-20, 6:30 pm

Thanks again for the links. I used the Sort Date algo to create EncodeSortDate() and DecodeSortDate() functions in SQLiteStudio. This will make working with the dates much easier.