C# method DateTime.TryParse() behaves differently on same machine in BizTalk versus Console app

Question

Consider the following lines of code:

DateTime d;
DateTime.TryParse("16-10-2020", out d);

When run inside a console app the date time 16-10-2020 00:00:00 is returned. Culture nl-NL is used, as defined in my windows regional settings. However, when run inside a Biztalk 2016 pipeline component on a 64 bit hostinstance, 16-10-2020 is not a valid date. Upon inspection it appears culture en-US is used to parse the date string. I did not explicitly specify any culture to be used in my code, therefore expecting nl-NL to be used by BizTalk as well.

Both scenario's are running on identical .NET Framework version on the same machine. What explains the difference in behavior?

I cannot find any specific culture configuration in my BizTalk server config. Could it be that BizTalk stored culture info somewhere I am unaware of during installation, but failed to update when regional settings changed? Just guessing. Anybody?

Answer 1

The BizTalk service account had different regional settings than my user, which explained the difference in behavior.

Better use TryParse exact if the format is known upfront.