A streak is a great motivator – until the first slip. One rough day and the counter drops to zero, even if you’ve done a lot over the past two months.
Activity age is a second, calmer measure. One number of days shows how steady you are over time. It grows slowly, a break only takes a little off, and a burst of checks on one day doesn’t make up for empty days. Here is everything worth knowing about it.
Streak vs. activity age
A streak rewards an unbroken run of days. Activity age rewards how long and how evenly you keep up with your topics – even when a break happens.
| Streak | Activity age | |
|---|---|---|
| What it measures | Days in a row | Consistency over time |
| One empty day | Back to zero | Down 10% |
| A day with half the target | Counts as a full day | Counts in proportion |
| Many topics, not all daily | Makes no difference | The daily target follows intervals |
| How fast it grows | +1 every day | At most +1 per full day |
How activity age is calculated
Every finished day gets a score from 0 to 1: the share of the daily target you checked in. The age then changes by a single formula, day by day, from the first day with an active topic up to yesterday.
age = age × 0.9^(1 − day score) + day score- +1A full dayScore 1: the age grows by one day and loses nothing.
- −10%An empty dayScore 0: the age loses 10%. That’s 4 days at 40 and 10 days at 100.
- ½A partial dayA bit of loss and a bit of growth, in proportion to the score. At age 20, a day with half the target ends at 19.5.
Today only earns a bonus, never a penalty: age today = age yesterday + today’s score. So the number never drops in the morning before you’ve had a chance to do anything. The full rule applies after midnight.
A day’s score is capped at 1. Ten checks against a target of 3 count the same as three – the age grows by 1, not 3.33. That’s why one intense day can’t inflate it.
Glossary
- Check
- Marking a topic done on a given day – at most one per topic per day.
- Topic interval
- How often you mean to do a topic: 1 = every day, 3 = every 3 days, 7 = once a week. Set it in “How often?” when editing the topic.
- Active topic
- A topic created on or before that day and not finished earlier. A finished topic still counts on the day it was finished.
- Daily target
- The sum of 1 / interval over all topics active that day.
- Day score
- Checks divided by the daily target, capped at 1.
- Day
- A calendar day in your time zone, not the server’s.
Daily target and intervals – why you don’t have to do everything every day
You have 10 topics, but one day you do 2 and the next day 3 others? That’s perfectly normal. Activity age doesn’t expect every topic to be daily – it follows what you planned.
Each active topic adds 1 / interval to the daily target. A daily topic counts as 1, “every 3 days” as ⅓ and “once a week” as 1/7. A topic without an interval counts as daily.
- 10daily topics = a target of 10 checks a day
- 5checks with 10 “every 2 days” topics = a full day
- 3.33checks a day with 10 “every 3 days” topics
Example: 5 of 10 topics
With 10 daily topics, 5 checks give a score of 0.5. At age 20 that day ends at 19.5, at age 5 it ends at 5.2. Keep that up every day and you settle around 10 days. Set those topics to “every 2 days” and the same day is full, worth +1.
If you have many topics and all of them are set to daily, your age will stay low even though you work regularly. Set realistic intervals – the daily target becomes fair and the number tells the truth.
Simulator: where does your pace lead?
Choose what your days look like and see how activity age changes over six months. Drag a finger or the cursor across the chart to check any day.
- after 30 days
- 7
- after 90 days
- 9
- after 180 days
- 9
- where you level off
- about 10 days
Day 180: activity age 9.7 days
Open Check!, set the intervals of your topics and see how regular you really are.
Open Check!The simulator assumes a repeating pattern of days. In the app, the age comes from your real check history and from daily targets based on your active topics and their intervals.
Where does the age level off?
At a steady pace the age stops growing where the gain from full days balances the loss from empty ones. For the pattern “this many full days, then one empty”:
| Consistency | Pattern | Age levels off around |
|---|---|---|
| 50% | 1 full day, 1 empty | 9 days |
| 80% | 4 full days, 1 empty | 36 days |
| 90% | 9 full days, 1 empty | 81 days |
| 95% | 19 full days, 1 empty | 171 days |
| 100% | no breaks | keeps growing |
That’s why 20 days is a good result after a month and a weak one after a year. The number itself isn’t a grade. The direction matters more.
A step-by-step example
Starting age: 20 days. Daily target: 3 checks (three daily topics).
| Day | Checks | Day score | Age |
|---|---|---|---|
| 1 | 3 | 1 | 21.00 |
| 2 | 2 | 0.67 | 20.94 |
| 3 | 0 | 0 | 18.85 |
| 4 | 3 | 1 | 19.85 |
| 5 | 1 | 0.33 | 18.84 |
| 6 | 3 | 1 | 19.84 |
| 7 | 3 | 1 | 20.84 |
The empty day 3 cost almost 2.1 days, but day 4 started making it up right away. After a week with one empty and two partial days, the age is still higher than where it started.
The app shows the whole number: 20.84 reads as “20 days”. Two empty days in a row at age 100 give 90 and then 81 – a noticeable drop, but nobody starts from zero.
Trend and colours – direction, not a grade
We don’t colour the number itself, because what it means depends on how long you’ve used the app. The colour only shows which way the age moved over the last 7 days. Next to the number you see a label such as “+5 this week”.
- Growinga change of +0.5 or morebrand colour
- Steadya change between −0.5 and +0.5a calm, light shade
- Droppinga change of −0.5 or moremuted amber
We never use red. Check! promises no guilt – a drop is information, not an alarm.
For the first 7 days there is no trend, only “Your age is taking shape”. With small numbers every change looks dramatic and says nothing yet.
The chart shows the last 90 days (30 and 365 in the details too). The last week is drawn in the trend colour, and a dot marks today’s value.
Milestones
The milestones are 7, 30, 50, 100, 200 and 365 days. A bar on the details screen shows how far the next one is, e.g. “To 50 days: 8 days”.
A reached milestone is saved to your account with its date, and nothing takes it away – not even when a rough week brings the age back below it.
A hint when the age drops
When the age is dropping, the app tells you what to do today: how many checks are missing for a full day (the daily target minus today’s checks, rounded up). One full day stops the drop.
Once today is full, you’ll see: “Today is a full day – your age grows by 1”.
What changes the result, and what doesn’t
- The age is always recalculated from historyIt isn’t a counter that gets bumped. Back-filling a day (up to 30 days back) or undoing a check changes it right away.
- Changing an interval recalculates the whole historyPast daily targets change too, so the number can jump up or down. Reached milestones stay.
- Adding or finishing a topic doesn’t rewrite the pastEach day’s target comes from the topics active on that day, not today.
- Days without active topics are skippedThe age doesn’t move – no penalty, no bonus.
- A topic that reached its goal stops countingUnless you chose to keep going after the goal, it can’t be checked, so it doesn’t weigh on the daily target after its last check.
- The last 2 years of historyThat’s how far back we look. Older days have next to no effect on today’s number anyway.
Putting it into practice
- Set realistic intervalsA topic you do twice a week belongs on “every 3 days” or a custom interval. The daily target becomes fair.
- Watch the direction, not the numberLast week’s trend says more than the value itself. A steady age is a good sign too.
- After a break, just come backAn empty day costs 10%, and a full one starts making it up straight away. No need to start over.
- A partial day counts tooNo time for everything? Do part of it – half the target still lifts a young age.
Frequently asked questions
Can I change the 10% penalty?
No. It’s a fixed rule, the same for everyone – that keeps the numbers comparable and easy to understand.
When does an empty day show up?
After midnight – that’s when yesterday is settled with the full rule. Until the day ends, today can only raise the number, so nothing drops during the day.
Does activity age replace the streak?
No, it’s an extra measure. A streak counts days in a row; the age shows how regular you are over time.
Where do I find it?
On the topic list in the app, above your topics. Tap the card to see a large chart, today’s target, milestones and your numbers.