It may take about 200 hours of spending time together before you consider someone a close friend. While it may be evident that spending time fosters closeness, it can be challenging to find time to socialize, especially between long-distance friends. One way to maintain friendships is staying in touch, even if virtually. Checking in with friends on their birthdays or special occasions is a thoughtful way to show them you’re thinking of them. You can also help by remembering the small details they mentioned, such as a vacation they had planned or a scheduled job interview.