I plan to implement this at some point, however, as mentioned, it would take more work than just updating the declarations. There are a number of places where time values are stored/manipulated in general use 32bit variables, which means I would have to track down every such use to update it.
When I start working on a 64bit version of mIRC (which I have attempted once or twice before - before realizing what a huge job it was!) robust declarations for 64bit variables will be needed and this will include time values. It will take quite a bit of work and testing as a 64bit version will require hundreds of codes changes.
