I have non-24-hour sleep disorder with a 25-hour cycle, and used to draw these calendars manually in Excel to track my shifting sleep schedule. Finally automated it.

Green cells show when you're awake. You can click any cell to toggle it (useful for marking unavailable times when sharing with others). The "padding hours" feature helps set buffer zones around sleep/wake times.

Been using this daily for months – thought others with non-24 might find it helpful too.