A worked example: counting down to December 31
Counting from September 12, 2026 to an event on December 31, 2026 gives 110 days remaining — 15 full weeks, with a status message reading "110 days remaining."
The formula: target date minus reference date
Days remaining = event date − count-from date, using whole calendar days with no time-of-day or timezone component. Weeks remaining is simply that day count divided by 7 and truncated to a whole number.
What happens once the date has passed
Counting toward a date that's already behind the reference date — say, June 1, 2026, counted from September 12, 2026 — returns a negative day count, −103, with the status switching to "103 days ago" instead of "remaining." The sign of the result is what flips, not the underlying arithmetic.
The single edge case worth knowing
When the target date and the reference date are the same day, the day count is exactly 0 and the status reads "Today!" rather than either a remaining or an ago message — a small but deliberate wording choice for the one case where neither "remaining" nor "ago" quite fits.
What this calculator assumes
Both dates are treated as plain calendar dates, with no hour or timezone attached — useful for whole-day events like a wedding or exam date, but not precise to the hour for an event with a specific start time later in the day.