Although Racoon seems to think you can be 100% sure that it will always be date - version, I disagree.
versions.txt is meant for reading, not parsing. Maybe one day Khaled might decide version - date looks nicer, it's a text file, that kind of change is something that should be expected. Formats for text files change all the time.
Additionally, saying it will _always_ be that way is imho flat out wrong. You can verify this by looking through the file:
27/04/96 - mIRC v4.1 (final bugfix release)
20/03/96 - mIRC v4.0 (final version)
13/09/95 - released mIRC v3.64 patch
13/08/95 - mIRC v3.51 (minor update)
29/06/95 - mIRC v3.42 (minor update)
21/06/95 - mIRC v3.3, v3.4
26/03/95 - mIRC v2.8c etc...
So you can see that it is NOT true that it will always be date - version because I've just shown 7 examples where it wasn't.