Today
A coherent day, not three random good ideas.
Use your group preferences, saved places, trip dates and what you have already done. Live weather and sea conditions improve the result when available, but the planner still works without them.
Your trip
Outside a private trip, dates and trip state stay on this device. Inside a private trip, they sync to the private trip. Live forecast requests go directly to Open-Meteo when you ask for them.
Already done
Marking something done keeps it out of future automatic days.
Build it yourself
Use an ordered timeline. No fake drag handle: reorder explicitly and the pack checks travel burden, timing and total length.