In reply to andy farnell:
Hi Andy, sorry about this. I've tested it in a lots of browsers and it's been fine in all of them.
I can't reproduce the problem here but I'll try and get it sorted for you. What browser/OS are you on please?
EDIT: I've just tried switching to your profile, clicked on My Logbook, edited it and it went through fine. It sounds like your browser isn't interpreting the allowed date fields correctly. It that's the case I'll try rewriting the checking method.
Post edited at 15:25