Guides
Short, plain-language explanations of the confusing parts of dates and time, each pairable with a tool on this site.
Guides
How to convert a Unix timestamp to a date
What a Unix timestamp actually counts, why 10-digit and 13-digit values differ, and how to convert one to a readable date without getting the unit wrong.
GuidesUTC vs local time
Why the same moment reads 09:00 in London and 17:00 in Tokyo, why offsets are not time zones, and how to write times that cannot be misread.
GuidesHow to calculate business days
How business-day counting works: start-exclusive counting, custom weekends, holiday lists, and the conventions that make two calculators disagree.
GuidesDaylight saving time, explained
Why clocks change, why spring-forward times don't exist and fall-back times happen twice, and how DST schedules differ between regions.