My personal take on it is that the schedules feature is just about useless on the default 100% time speed, if you have anything other than extremely short (maybe that should be absurdly short…) lines. At 100% time speed, my recommendation for realistic line lengths is to basically mostly disable schedules in favour of a single 24x7 uniform schedule (or maybe a 24x5 + 24x2).
To make journey times seem "about right", I go for 20% time speed, and can then make reasonable use of day/night/rush/weekend schedules. That works pretty nicely for me, apart from one relatively significant issue, which is that the max fast-forward speed is far too slow, with a game day taking too much real time. What I'd really like is a way to speed the vehicles up significantly (to a reasonable approximation of real-world speeds), but keep the default simulation time acceleration, which doesn't seem to be possible right now — we need either a not-time speed rule, or a way to adjust the simulation fast-forward / time acceleration factors.