How the countdown is measured
The calculator converts both the target date and the "from" date to timestamps, subtracts the from date, and divides by the length of a day to get a whole number of days. A positive number means the target is still ahead of you; a negative number means it has already passed and the headline shows it as "days ago".
Leave the "from" date set to today for a live countdown, or set it to any other date to ask "how many days between these two points" from a fixed vantage point.
Reading the breakdown
A raw day count is precise but hard to picture once it runs into the hundreds, so the result also gives you the same span in weeks and as a months-plus-days figure. The months-and-days breakdown uses calendar months: it advances whole months from the earlier date until adding one more would overshoot, then counts the leftover days.
Because months vary in length, the weeks figure and the months-and-days figure describe the same gap two different ways; pick whichever is easiest to act on.
Tips and caveats
Worth knowing:
- The count is at whole-day resolution and ignores the time of day, so an event later today shows as zero days, not a fraction.
- A result of "Today" means the two dates are the same.
- For business-day countdowns (excluding weekends and holidays) use the work days calculator instead.
- Targets far in the past or future stay accurate because the math is plain calendar arithmetic.
Formula
diffDays = floor((targetDate − fromDate) / 86400000)Frequently asked questions
- What does a negative result mean?
- The target date is in the past relative to the "from" date, so the figure is shown as days ago.