Date conversion issue when patching

[BrendanZ1]

Hi all,

I have been looking at numerous date patching issues in the forums here, but none seem to match what I am experiencing.
Most issues relate to a direct change in date format (usually swapping month and day order for US vs AUS formatting). For me, it seems that the date being saved is almost random and nothing like what has been recorded in the app.

My example:

Initial date picker that establishes a date that will then be patched numerous times: 
control name: dpExpiryDate
DefaultDate: Text(ThisItem.ExpiryDate, "[$-en-US] dd/mm/yyyy")
Format: "dd/mm/yyyy"

The date showing in the date picker is: 08/06/2025
Yet the date saved (which is correct) is: 30/08/2023

So at this stage I am patching to SharePoint and it is saving the date as desired. (please note I have checked regional settings which are set for AUS).

The next step is to create a collection that uses 'ThisItem.ExpiryDate'. In this instance it uses the following: 
ExpiryDate: DateValue(Text(lblExpiryDateData_1.Text)) - the label is displaying the ExpiryDate as Text(ThisItem.ExpiryDate, "[$-en-US] dd/mm/yyyy")

The moment I add 'DateValue', it states that the date equals 6/8/2025 instead of 30/08/2023.....
So in the end, while I can get my original expiry date to save as required, any further saving of this data field into a collection or patching to a second SharePoint list generates what seems to be a random date value (not really random - just don't have the brains right now to figure out the pattern)

Hopefully this is clear enough to follow?

[RandyHayes · Accepted solution]

@BrendanZ1 

You need to specify the region information in your controls.  

The date is not random, it is actually the conversion of month 30 of 2023.  You say, "what is month 30?" - so does PowerApps...so it really just adds it on to Jan of 2023.  Month 30 would be 2 years and 6 months in the future...or, June 2025.  

So, your DefaultDate on your datepicker should be: ThisItem.ExpiryDate

You are currently converting a date to Text for the DefaultDate Property - WHICH expects a Date, not a text value.  This means that it will then (without your specific direction to do so) have to convert it from the text that it is into a date value.

So, instead, use the above (just the date) to assign to the property and it will not do any conversion that you don't want.

Next thing is to set the language on your datepicker.  Go to the Language property and put in your regional language code there to specify the language conversions you want to always occur.

It is important to observe, and provide where needed, the appropriate language code.  This can not only be provided on the Language property but also in Text and Date conversion functions.

I hope this is helpful for you.

[BrendanZ1]

@RandyHayes Thanks heaps for the new knowledge - I wasn't aware of the language property with the DatePicker.

I now have a lot of work to do on a number of apps rectifying this to avoid the same issues happening.

It has fixed the issue and although I knew there would be logic behind the date being generated, glad you provided a shortcut to understanding what is happening.