Countdown and Elapsed Time: Timers That Work
Counting toward and away from a moment, the three choices that define a finish line, round-number milestones, and the live timer’s hidden assumptions.
Time & Date Guides
Calendar math done right: day counting conventions, leap years, business days, time zones, Unix timestamps and timesheet arithmetic. The three places date calculations genuinely go wrong, and how to keep them reliable.
Time Zones: Convert Meeting Times Without Mistakes
Three traps hide in timezone math: staggered DST switches, the two ambiguous twelves, and the date line. All three, made mechanical.
Business Days vs Calendar Days (and Leap Years)
The two counts side by side, day-zero and rollover conventions, why holidays defeat automation, and the weeks trick that makes estimation easy.
Timesheet Math: Add Hours and Minutes Correctly
Hours and minutes are base-60 pretending to be decimal: the carry rule, the 7.45 trap, a worked week of shifts, and where payroll cents leak.
Unix Epoch Time: Why Computers Count from 1970
Every log and API speaks a number near 1.78 billion: why 1970, how to read epochs at a glance, and the two traps that bend dates by millennia.
Date Difference: Days Between Dates Done Right
Calendar math is tricky in exactly three places: endpoint counting, leap years, and the month that has no fixed length. All three, settled.
Date and Time Tools: Calendars, Clocks and Time Zones
Date and time tools handle a kind of arithmetic that looks simple and is quietly full of traps. Months have different lengths, some years carry an extra day, clocks run on two competing formats, and the world is divided into time zones that do not line up neatly. A single overlooked rule can throw a … Read more