Check if date is 2 weeks, 4 weeks, so on. From specific date

Targets Web
1

Xojo 2022r4.1 on Windows 10
How would I check a date that is selected with webdatepicker to verify that the selected date is 2 weeks, 4 weeks, 6 weeks ect. from a specified date. I want to only allow a date that is on a Friday paydate. Pay is every other Friday. I will supply the starting pay Friday date in my code.
I have not tried any code yet. Was hoping that someone has already solved this.
Thanks

2

Wouldn’t a (invervalBetweenDatesInDays \ 7) enough ?

3

Too bad that DateInterval does not offer .TotalDays

4

@Rick_A
I will try that. But I don’t believe that will solve my issue.
Example, My fixed date will be June 2, 2023 and I need to check if the selected date is exactly 2 weeks, 4 weeks, 6 weeks, 8 weeks and so on, from June 2, 2023. The fixed date will never change.
Maybe that makes sense.
Thanks

5

Use mod 14 instead. You still need to calculate the IntervalBetweenDatesInDays.

6 

Var baseDate As New DateTime(2023,6,2) // June 2, 2023

Var aDate As New DateTime(2023,6,16) // proper date

Var interv As DateInterval = aDate - baseDate

Var isProper2weeksModFromBase As Boolean = interv.Days mod 14 = 0  // true
7

Your code doesn’t work if the interval is more than 1 month.

8

I see. Then


Var baseDate As New DateTime(2023,6,2) // June 2, 2023

Var aDate As New DateTime(2023,6,16) // proper date

Var intervDays As Integer =  aDate.SecondsFrom1970 \ 86400 _
                             - baseDate.SecondsFrom1970 \ 86400

Var isProper2weeksModFromBase As Boolean = intervDays > 0 _
                                           And intervDays mod 14 = 0 // valid date
3 Likes
9

Rick created a Feature request about the .TotalDays some time ago:

#66479 - DateInterval needs TotalDays and TotalSeconds

2 Likes
10

That works great. Thank you for all the help.
and Thanks @AlbertoD for your help also.

3 Likes
11

DateTime also has WeekOfYear so you can just calculate from the current DateTime.Now.WeekOfYear

12

I don’t know how this will help if:

  • the date is in another year
  • the date selected is not a Friday in the same year (some other calculation needs to be done and not just WeekOfYear

The user is selecting a date with webdatepicker.