Format dates and times

Format dates and times in JavaScript — with the four heights of help laid out: do it now, make it easier for the next person to accept, work out the right move when you are stuck, and learn the pattern so it stops coming back.

4prompt heights
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The four heights

The same task, four distances: today's deadline, the next reviewer, the stuck moment, the pattern.

Execute — do the immediate task

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The dashboard shows timestamps as raw ISO strings. Convert the createdAt and updatedAt fields to…
The dashboard shows timestamps as raw ISO strings. Convert the createdAt and updatedAt fields to user-local format: show date as MMM DD, YYYY and time as HH:mm in the user's locale, updating when the timezone changes. Make sure this runs on page load and when the user switches accounts, ready for Monday's demo.

Improve — make it easier to accept

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Before I ship this to the UX lead, make the date formatting easy to review: put the format function…
Before I ship this to the UX lead, make the date formatting easy to review: put the format function next to the display component, show an example input and output at the top, and flag any places that still call toString on the Date object or assume UTC.

Decide — diagnose the stuck moment

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Users in CET see times shifted by several hours after daylight saving; I used fixed timezone…

times show wrong timezone for some users

Users in CET see times shifted by several hours after daylight saving; I used fixed timezone offsets when formatting timestamps for the activity feed. I can't reproduce locally because my machine is in PST. What's likely causing the DST shift and the safest fix to ensure dates render correctly across timezones without requiring server changes?

Become — change the pattern

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We keep wasting cycles because each component formats dates differently, introducing layout shifts…

formatting logic duplicated and brittle

We keep wasting cycles because each component formats dates differently, introducing layout shifts and timezone bugs. Which habit should we change to reduce bugs: where to centralize formatting, a small API for relative vs absolute time, and one test to prevent regressions?

Next to this one

Other programming language work people do in JavaScript.

Every task here came from the work, not from a feature list — which is why the prompts name what you want done and never the button that does it. The tool changes; the work does not.
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The rest of the map

Same library, five ways in.