Date & time
Age and date differences: decide what you are counting
Separate calendar age, elapsed dates and working days, including calendar choice and inclusive counting.
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Understand the idea. Put it to work.
Date & time
Meetings across cities: why a time needs a date
Understand time zones versus UTC offsets and avoid missing or repeated local times around daylight-saving changes.
Date & time
Days between dates: should both endpoints count?
Distinguish elapsed calendar days from an inclusive list of dates, and account for leap years without confusing days with hours.
Date & time
Adding days without creating deadline confusion
Anchor the starting date, distinguish 30 days from a month and separate date arithmetic from deadline conditions.
Date & time
Business days: why subtracting two days per week is not enough
Understand inclusive endpoints, custom weekends and holidays without deducting the same date twice.
Date & time
Countdowns: plan a short duration without confusing it with a deadline
Choose a clear duration, distinguish paused time from elapsed clock time and understand browser alert limitations.
Date & time
School-start age: an age calculation is not an admissions decision
Compare a birth date with a school’s actual assessment date and age requirement without mistaking the result for official admission.
Date & time
Unix timestamps: check the unit before trusting the date
Distinguish seconds, milliseconds and UTC, and treat a timestamp as an instant rather than a hidden local calendar.
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We develop original explanations and examples with automated assistance, then check calculations and factual claims against the cited sources. ToolRoof is an editorial credit, not a claim of expert review or personal advice. We correct verified errors and change update dates only for substantive revisions.
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