He's quiet for three days but you have plans: what to send

Start with his last message. If it was warm, specific, and he suggested something himself, the silence is more likely logistics or a busy week than a change of mind. If his last text was a flat one-word reply, or he trailed off mid conversation, the gap was already a signal before the plan existed. Check his pattern too. Does he usually take a day to answer, or is this the first long gap? Look for clues in what he has said about his week, like a work trip, a deadline, or a family thing. Three days is long enough to ask and short enough that it doesn't yet mean he has checked out. Let your read decide how much you say, and whether you say anything at all. If his history with you is thin, the plan is the only solid thing you know about him right now, so treat it that way.

Open by treating the plan as settled, because that's what he agreed to. Name the day, time, and place again in a way that only needs a yes. Leave the silence out entirely, since mentioning it turns a logistics message into a conversation about his behavior. Don't ask why he went quiet. He can explain if he wants to, and asking hands him a reason to get defensive. Keep the message short enough that replying takes five seconds. Add one small detail that shows you're looking forward to it, like the restaurant name or a question about which entrance to use. Give him a way to adjust if he needs to, such as offering to move it an hour later, so a no is easy to say and a yes is easy to give.

Send it in daylight, ideally late morning or early afternoon on the day before the plan or the morning of. A late night message after three days of quiet reads as either anxious or irritated, and he'll feel that before he reads the words. If there's no reply by the evening before, send one more short logistics message the next morning with no new commentary about the gap. Give that second message a few hours. If it still gets nothing, stop chasing. Decide ahead of time whether you'll go if he shows up without confirming, and whether you'll cancel if he doesn't answer at all. If you cancel, do it in one line that doesn't accuse him of anything, then drop it without a third message.