Could ask svchost about doing calendars in HTML, if you wanna see him have battle flashbacks.
Simplest implementation: list of strings, each string prefixed with a ascii-sort-able prefix like ISO dates. i.e.
2021-10-18 The day Mozai finally asks that boy on a date
2021-10-18:17:18 Rejection-comfort party for Mozai
What else do we need other than a prescribed "when" value and a freeform string "what" value? Maybe a freeform string "where" value?