What helps
An important birthday is not a chance to talk about yourself, or to settle months of silence. The reply is about them. The wish is one sentence.
If you know something that is theirs — a project, a habit, a party they mentioned — name it. Otherwise a sincere sentence is enough. The size of the message does not measure the attention.
Before the day, you save the wish for the day. Afterward, you do not stretch the party if they have moved on, and you do not turn it into a report of the evening.
Concrete example
"Happy birthday. That party you mentioned — I'm thinking of it."
Key takeaway
- The detail, not the speech.
- You do not repair a silence with a birthday.
Try next time
On the day, wish it and name a detail of theirs if you have one. Then stop.