You were at work late. They were at their grandmother's. It was Saturday and nobody thought about it. None of those are facts about the child, and a chart that renders them as an empty box, a zero or a gray square is stating something it does not know.
This matters more than it sounds, because a child reading a row of blanks does not read "no data". They read "nothing good happened for four days".
Blank, zero, and gray are three different claims
| How it is drawn | What it says | Is that true? |
|---|---|---|
| A zero | They earned nothing that day | No — nobody looked |
| A gray or crossed box | Something went wrong here | No, and it looks like a mark against them |
| Nothing at all | This day is not part of the record | Yes |
Which means: never build a streak
A streak is the same mistake wearing a friendlier face. It is a number that can break, and the thing that breaks it is usually an adult being busy. A child who loses a 19-day streak because you were in a meeting has been punished for your calendar.
Count the total instead. A total does not care whether the days were consecutive, cannot be broken by a holiday, and is the only shape that survives a real family's actual week.
If you want a rhythm rather than a streak, tie the chart to a moment you already have — the walk back from school, the five minutes after teeth. Not a daily obligation you will fail on the first busy Tuesday.