The date is coming. You can see it on the calendar like weather. Anniversaries don't need a script - they need a shape, something for the day to hold onto so it doesn't just hang there.
Light something
A candle at the time it happened, or at dinner, or at dusk. Fire is the oldest way humans have said someone mattered. It asks nothing of you but a match.
Cook their dish
The thing they always made or always ordered. Eat it slowly. Tell whoever's at the table one story about them - or tell the empty kitchen; it listens fine.
Walk their route
The dog loop, the way to the shop, the beach they loved. Walk it at their pace, not yours. Notice what they would have noticed.
Say their name out loud
Once, on purpose, sometime during the day. To someone, or to the room. Names are how the dead stay in the world; use it.
Or hide inside the day entirely - phone off, covers up, world cancelled. A hard date survived is a hard date honored. There's no wrong way to get through the 14th of anything.