A short walk together can keep a friendship present through a crowded season.

Friendship needs contact more than it needs occasions. During busy stretches the plans requiring an evening, a booking and a free weekend become impossible, so nothing happens at all, and closeness quietly turns into fondness at a distance. Small repeatable contact keeps a friendship in the present tense while everything else is full.

Suggest a walk instead of a dinner: half an hour, near one of you, no arrangements. Do it during a lunch break or on the way to something else. Regularity does more for a friendship than a rare evening you both have to prepare for.