500 Days Together: What the Milestone Means and How to Work Out the Date
Somewhere between the 100-day milestone that everybody knows about and the 1000-day one that feels genuinely enormous, there is a quieter number that couples keep finding on their own: 500 days.
It is not a monthsary. It does not line up neatly with any anniversary. Nobody handed it to you. That is more or less the appeal — it is a date you have to actually count to, which means it is the kind of milestone you notice only if you have been paying attention.
How to work out your 500 days date
Count 500 days forward from the day you started dating, counting day one as the first full day. The shortcut most people want: 500 days is one year, four months and about a fortnight, depending on where the months fall and whether a February with 29 days landed in between.
Two things trip people up. First, leap years. If a 29 February sits inside your 500 days, your date lands a day earlier on the calendar than a mental year-plus-four-months estimate suggests. Second, the day-one question. If you count your first day as day zero instead of day one, every milestone you ever celebrate shifts by one — which is fine, as long as you and your partner picked the same convention.
If you would rather not do the arithmetic at all, our days-together counter does it from your start date and keeps running, so the next milestone is already waiting rather than something you have to remember to calculate.
- •500 days ≈ 1 year, 4 months and 2 weeks
- •It usually falls about 5 weeks after your 16-month monthsary
- •It is roughly halfway between your first and second anniversary
- •A leap day inside the window pulls the date one day earlier
Why 500 and not 16 months
Month-based milestones and day-based milestones measure two different things, and couples tend to gravitate to one or the other without quite noticing.
Monthsaries are calendar events. They repeat, they are easy to remember, and they are shared — every couple who started on the 14th celebrates on the 14th. Day counts are personal. Nobody else in the world has your 500th day. That is why they tend to appeal to people a year or two in, when the monthly celebration has settled into a routine and the novelty has worn off slightly.
There is no rule that you pick one. Plenty of couples keep the monthsary for the small monthly check-in and save the day counts for the bigger, rarer ones. If you are still deciding how you want to handle the two systems, we compared them properly in our piece on monthsary versus anniversary.
What 500 days actually marks
The honest answer is that it is not a developmental stage. Relationships do not change on day 500. But the window it falls in — somewhere past the first anniversary, not yet at the second — is a genuinely distinctive one.
It is usually the first stretch where the relationship stops being new. You have been through at least one full cycle of birthdays, festivals, one bad week at work each, and probably one argument you both still reference. The performance of the early months is over. What is left is the version of each other you actually live with.
That makes 500 days a better moment for taking stock than for a grand gesture. If you want the celebration to mean something, aim it at that: the ordinary version of the relationship, not the highlight reel.
Low-effort ideas that still land
The best 500-day ideas are specific rather than expensive. Five hundred is a number you can build something around, which is more than you can say for most milestones.
- •Send 500 seconds of voice notes — that is eight minutes and twenty seconds, which is much longer than it sounds and much harder to fake
- •Redo your first date, at the same place, ordering the same thing, and note out loud everything that is different now
- •Write down 5 things you did not know about them on day 1 — one for each hundred days
- •Make a shared playlist capped at 500 minutes and take turns adding to it over the following weeks
- •Print a photo from roughly every 100 days and put them in order; the drift in how you both look is the point
- •Cook the worst meal you ever made together, deliberately, as a joke that only the two of you will get
A note on not overdoing it
One genuine risk with day-count milestones is milestone fatigue. If you celebrate the monthsary, the anniversary, 100 days, 365 days, 500 days and 1000 days, you are marking something roughly every six weeks, and each one gets a little thinner.
If that is starting to feel like admin rather than affection, pick two and drop the rest. A milestone works because it interrupts the ordinary run of things. If nothing is ordinary, nothing interrupts.
And if your partner is simply not a milestone person — some people genuinely are not — 500 days is a good one to mark quietly on your own side. Noticing is not the same as demanding a celebration.
What comes after 500
The next few worth knowing about: 600 days lands about three months later, day 730 is your second anniversary, and day 1000 arrives around two years and nine months in — the one that genuinely surprises people with how far away and then how suddenly close it gets.
Set the start date once, and let the counting take care of itself. The point of a counter was never the number. It is that you get told, on an otherwise unremarkable Tuesday, that something has been going on for longer than you realised.