Weather's beaten you? On the Schedule, open the day and use Rain-off. It suggests a target day (the driest day in the week with the least work already booked), moves every visit across, and texts or emails each affected customer so nobody's waiting in for a crew that isn't coming.
Get told the evening before. With Weather washout alerts on (Settings → Automations), the office gets a nudge around 5pm when tomorrow looks like a wash-out: how likely, how much rain, how many of tomorrow's tasks actually mind it (mowing, spraying, seeding do; fencing and tree work don't), and which dry day has room. Tap it and Rain-off opens already aimed at that day, so customers hear tonight instead of at 7am.
You see the whole plan — which visits, where to, who gets told — before confirming. Fixed-price contract work keeps its billing; nothing invoices twice because a visit moved.