Agreed. However, seems very unlikely to me that any PC would fail to understand "dd MMM yy", especially a standard-build company PC, and especially when it works on one but not another.
in this case, it was actually being pulled in as part of a string from another system in a specified format, and I was simply turning it into a date to store in a date variable.

Woe betide those who think they can get away without needing exception-catching in a simple 3-line date-conversion proc which always has a standard-format input.