Trip-length scaling
Entering a start and end date sets the baseline quantity for repeatable items such as shirts, socks, and underwear, with the list assuming you'll do laundry or re-wear items rather than packing one full outfit per day on longer trips. This same date range also anchors the season and climate tagging described below. Shorter trips get a leaner list; multi-week trips add categories like laundry supplies rather than scaling clothing linearly.