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

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

Wouldnâ€™t a (invervalBetweenDatesInDays \ 7) enough ?

Too bad that DateInterval does not offer .TotalDays

@Rick_A
I will try that. But I donâ€™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

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

``````
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
``````

Your code doesnâ€™t work if the interval is more than 1 month.

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

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

#66479 - DateInterval needs TotalDays and TotalSeconds

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

3 Likes

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

I donâ€™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.