Convert String to DateTime in C# UK and US format

Question

I am trying to convert a string to a datetime

I have been using

DateTime convertedDate = DateTime.Parse(lastModificationDate);

to convert the date

my problem is, sometimes the date will be in UK format and sometimes in US format

ie UK 11/09/2011 10:34 US 2/28/2010 13:56

How can I handle both formats when I am not sure which format the string will be in, ie us or uk?

Answer 1

You fundamentally can't. You don't have enough data. As a human, which date is involved here?

11/09/2011 10:34

Is that 11th of September or 9th of November?

If you can't tell the difference as a human, there's no chance of a computer doing so.

Now if you can get a signal from elsewhere in the same data source, then that's a start - for example, you could heuristically try to parse all the dates as US format, and all the dates as UK format, and if 100% pass as UK format but 60% fail in the US format (due to trying to days being parsed as invalid months) then you could reasonably assume they're UK dates.

That's never going to be a complete solution though - because you could have one data source with a bunch of dates which are all valid (but with different meanings) in both formats.