Most confusion about anniversaries comes from mixing two different things: counting days and counting years. They use different units, so it helps to treat them separately.
There is no correct way to count days — just pick one
Some people call the starting day day one; others call it day zero. Neither is wrong. The problem is when two people count differently and end up with different dates for the 100th day.
- If the start day is day one, the 100th day is the start date plus 99 days
- If the start day is day zero, the 100th day is the start date plus 100 days
- Either is fine — agree once, and write it down
Apps and tools differ here too, which is why two counters can be one day apart. If you notice a mismatch, check which convention each one uses.
Years are counted by date, not by days
An anniversary in years lands on the same month and day as the start date. Counting in days does not work here: depending on whether a leap year falls in between, one year is either 365 or 366 days.
If the date is 29 February, decide in advance whether you celebrate on 28 February or 1 March in other years.
Work out the milestones ahead of time
Day 100, day 200, day 365 and day 1000 tend to be the ones people notice. Realising on the day itself is too late to book anything, so it helps to know the dates in advance and be reminded before they arrive.
None of this is specific to couples. A wedding anniversary, a child's birthday, the day you adopted a pet — the same approach works for any date worth remembering.
Build the reminder into your day
Forgetting an anniversary is usually a systems problem rather than a memory problem. If nothing in your day points at the date, you will not think about it until it arrives. Any of these three helps:
- A repeating calendar entry with a notification a few days before
- A Home Screen widget showing the days remaining, so you see it without opening anything
- A short note about what you did, so next year has a starting point
Cherimo covers all three. Save a date and you can see both the days remaining until it comes round again and the days elapsed since it happened. The same counter works as a Home Screen widget on iPhone and Android, and dates can repeat yearly or monthly.
What you save is yours alone. There is no way to invite the other person, so nothing you are planning is visible to them.