There is no date / time format string in the Windows API. It has separate date and time format strings.
.Net has DateTimeFormatInfo.FullDateTimePattern , but looking in Reflector it seems to be initialized:
LongDatePattern + " " + LongTimePattern
and the value that it has for all 354 cultures on my Windows 7 PC. You would only see what did not match this pattern if the program created a custom .Net culture and defined it differently.
I worked on software that was sold all over the world, and no one ever complained that we were using a date and time separated by a space.
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