Capacity Planner - Calendar-Based Capacity Calculator

A zero-dependency single-file tool I built for my own day-to-day capacity planning. When I need to figure out how many work hours fit into a month, distribute them across workdays, or quickly check available capacity for a date range - I open this page. It lives in my homelab as a tiny public app and gets deployed via FluxCD like everything else.

Key Features & Details

• Two distribution modes: Spread evenly distributes hours proportionally across all available workdays; Compress front- or back-loads hours into fewer full workdays up to a configurable daily max
• Year overview: 12-month grid with per-month capacity inputs and live scheduled/avg stats - click any card to jump to that month's calendar
• One-off exceptions: Mark individual days as full day-off or set partial hour-offs (for things like half-day meetings); exceptions can apply to a single day, all same weekdays in a month, or all same weekdays in a year
• Date range filter: Set a start/end boundary and instantly see total scheduled work hours and workday count for that interval
• Overtime mode: Optional flag to allow the last fill day in a week to absorb leftover hours beyond the daily cap
• Import / Export: Full state round-trips as a JSON snapshot - useful for saving plans or sharing them
• Dark mode: Persisted via localStorage, no flicker on load
• Deployed on homelab: Served as a static file via nginx, exposed through Traefik + Cloudflare, managed by FluxCD GitOps

codeCopy
[ Inputs sidebar ]  ──►  [ Calendar grid ]  ──►  [ Stats bar ]
   mode, date range          color-coded days        capacity / avg
   max hours, fill order     click to edit           scheduled hours
   exceptions list           day-off badges

Built as a single HTML file with vanilla JS and Tailwind CDN - no build step, no framework, no dependencies. Runs anywhere a browser exists.