Birthdays, work anniversaries, client anniversaries — three screens work together: add dates one at a time, catch up on everyone missing one, then follow up on what's coming.
On a Person, Company, or Employee's own detail view, use the Important Dates tab — Add Important Date, pick a Type, a Date, optional Notes.
Side menu → Add Important Dates in Bulk. Pick a Type and who it applies to:
It lists everyone of that kind who doesn't already have a date of that type, with an inline date picker per row — check off several and save at once. Meant for a one-time catch-up pass (e.g. backfilling birthdays for existing contacts), not day-to-day entry.
Side menu → Upcoming Dates. Shows everyone with a date falling within the next 7/14/30/60 days (your choice), with a one-click Send that emails them directly from the row.