Can I set a Memory’s start and end dates?

You can, and it takes four taps: ⋯ → Memory Settings → Details, then Set dates manually under Time & Place. Most of the time you won’t need to. A Memory works its own dates out from the Moments inside it: the earliest one and the latest one. Add something older and the start date moves on its own.

Setting them yourself

1. Open the Memory and tap ⋯ → Memory Settings.
2. Tap Details.
3. Under Time & Place, turn on Set dates manually.
4. Tap Start and pick a date. Do the same for End.

While the switch is off, Start and End are greyed out and show the dates Lumoria worked out. Turning it on makes them tappable. Those worked-out dates stay behind as grey hints until you choose your own.

There’s no Save button here. Each change is written as you make it, so you can leave the screen the moment you’re done. Turn the switch back off and the dates follow the Moments again. Nothing inside the Memory changes.

Remind me every year

The switch under the two dates. It marks this Memory as one you want back on its anniversary. Today it records that choice and no more: Lumoria isn’t sending the yearly reminder yet. On this day is the notification that looks back for you in the meantime, and “Which notifications does Lumoria send?” lists every one.

These two dates belong to the Memory as a whole. Every Moment keeps its own date as well, and that’s what Sort… in the ⋯ menu reads when it puts the grid in order.