But it has everything to do with strptime, if DateTime has this (newer) POSIXMEHARDER style approach. There's no reason this roll-over couldn't be handled in the module. I see 24:00 as being an exceptional case, a rather common and concise means to specify a *whole* day, without having to do any math on the date itself.
All I've found is this thread "date normalization" http://marc.theaimsgroup.com/?l=perl-datetime&m=105713352122992&w=2 -- H4sICNoBwDoAA3NpZwA9jbsNwDAIRHumuC4NklvXTOD0KSJEnwU8fHz4Q8M9i3sGzkS7BBrm OkCTwsycb4S3DloZuMIYeXpLFqw5LaMhXC2ymhreVXNWMw9YGuAYdfmAbwomoPSyFJuFn2x8 Opr8bBBidccAAAA= -- MOTD on Pungenday, the 65th of Discord, in the YOLD 3172: I've lost all sensation in my shirt