A friendship across places needs an agreement that survives imperfect timing.

Distance turns friendship into something arranged rather than encountered. Messages cross, replies take a week, calls get postponed twice, and without an understanding about that, the gaps start being read as evidence of how much either person cares. What holds it together is an agreed tolerance for bad timing. The friendship is not the frequency.

Tell your distant friend that slow replies mean nothing between you. Put one thing in the diary instead of waiting for a good moment. Send the unimportant message, since the small ones keep the line open.