When does my Handicap Index update, and how does it stay active?

Under Rules 1.4, 5.4 and 5.5 of the 2024 Rules of Handicapping:

• Update timing: your Handicap Index should be updated no later than the day after you submit a score. If you play again before it updates (including two rounds on one day), the recommendation is to use your existing Handicap Index, although the Committee in charge of a competition or the Handicap Committee can decide which Playing Handicap you use.
• Which scores count: a score stays in the calculation for as long as it is within your most recent 20 scores, regardless of its age.
• Lapsing: a Handicap Index only lapses if you are no longer a member of at least one golf club. Your scoring record should be kept where possible.
• Joining a club: you need to be a member of a golf club affiliated with an Authorized Association (or a direct member of one that has taken over the responsibility of a club).
• Home club: you must designate one club as your home club, responsible for maintaining your Handicap Index. If you belong to more than one club, make sure each knows about the others and which is your home club.
• Professionals: a professional golfer may obtain a Handicap Index if they meet all the player responsibilities.