Days Between Dates Calculator: Count Days & Months

What does 300 days mean?

It means January 1 and October 28, 2026 are 300 midnights apart: from Thursday, January 1, 2026 to Wednesday, October 28, 2026 is 300 days, 42 weeks and 6 days, 9 months 27 days, 7,200 hours and 432,000 minutes. The count is the difference of the two midnights, so the start date itself is day zero and the end date is day 300 — and if you count both ends, the span covers 301 days. Weekdays are counted in the span itself, not estimated from the weeks: 214 of the 300 days are weekdays, 86 are weekend days, and 215 weekdays fall in the span counting both ends.

Three things to check before you trust the number

Days, weeks and months are three different counts. 300 days is 42 weeks and 6 days — 42 whole weeks plus 6 days left over — and 9 months 27 days, which is 9 whole calendar months to October 1 plus 27 days. The weeks divide evenly, the months follow the calendar, and neither is the other: 42.857143 weeks is the unrounded figure, and it is not 9 months 27 days in another costume.

Months follow the calendar, not 30 days. A month is January to February, not 30 days: January 1 to February 1 is 1 month, February 1 to March 1 is 1 month, and January 31 plus one month is February 28, not March 3. The calculator counts whole calendar months first, then the days left over, so the months figure always lands on the same day of the month where one exists.

Inclusive and exclusive are different answers. From January 1 to October 28 is 300 days, and 301 days inclusive — the difference is whether you count the start date itself. Hotel nights, ages and deadlines usually want the exclusive count, 300; a trip that runs January 1 through October 28 covers 301 days. Say which one you mean, or the answer is off by one.

Worked example

On the defaults: January 1, 2026 to October 28, 2026.

1. Days: October 28 minus January 1 = 300 days.
2. Weeks: 300 ÷ 7 = 42 remainder 6, so 42 weeks and 6 days (unrounded 42.857143 weeks).
3. Months: January 1 plus 9 calendar months is October 1, and October 1 to October 28 is 27 days, so 9 months 27 days.
4. Hours: 300 × 24 = 7,200 hours.
5. Minutes: 300 × 1,440 = 432,000 minutes.
6. Weekdays: 42 whole weeks give 210 weekdays, and the 6 leftover days — Thursday to Tuesday — add 4, so 214 weekdays (215 counting both ends).
7. Weekend days: 300 − 214 = 86 weekend days.
8. Days inclusive: 300 + 1 = 301 days.
9. Smallest end date for at least 300 days: October 28, 2026 — October 27 is 299 days.
10. Add 100 days: January 1, 2026 plus 100 days is Saturday, April 11, 2026.

Every branch, checked

• One whole year: One whole year: From Thursday, January 1, 2026 to Friday, January 1, 2027: 365 days; 52 weeks and 1 day; 12 months 0 days; 8,760 hours; 525,600 minutes; 261 weekdays (262 including both ends); 104 weekend days; 366 days inclusive. one whole year — January 1, 2026 to January 1, 2027 is 365 days, 52 weeks and 1 day, 12 months exactly, because 2026 is not a leap year.
• A leap year: A leap year: From Monday, January 1, 2024 to Wednesday, January 1, 2025: 366 days; 52 weeks and 2 days; 12 months 0 days; 8,784 hours; 527,040 minutes; 262 weekdays (263 including both ends); 104 weekend days; 367 days inclusive. a leap year — January 1, 2024 to January 1, 2025 is 366 days; the extra day is February 29.
• February 2026: February 2026: From Sunday, February 1, 2026 to Sunday, March 1, 2026: 28 days; 4 weeks and 0 days; 1 month 0 days; 672 hours; 40,320 minutes; 20 weekdays (20 including both ends); 8 weekend days; 29 days inclusive. February 2026 — February 1 to March 1 is 28 days, 4 weeks exactly, because 2026 is not a leap year.
• The same date twice: The same date twice: From Wednesday, October 28, 2026 to Wednesday, October 28, 2026: 0 days; 0 weeks and 0 days; 0 months 0 days; 0 hours; 0 minutes; 0 weekdays (1 including both ends); 0 weekend days; 1 day inclusive. the same date twice — 0 days, but 1 day inclusive, because the day itself still counts.
• Add 100 days: Add 100 days: Thursday, January 1, 2026 + 100 days = Saturday, April 11, 2026. add 100 days — January 1, 2026 plus 100 days is Saturday, April 11, 2026.
• Subtract 30 days: Subtract 30 days: Wednesday, October 28, 2026 − 30 days = Monday, September 28, 2026. subtract 30 days — October 28, 2026 minus 30 days is Monday, September 28, 2026.
• The millennium so far: The millennium so far: From Saturday, January 1, 2000 to Wednesday, October 28, 2026: 9,797 days; 1,399 weeks and 4 days; 321 months 27 days; 235,128 hours; 14,107,680 minutes; 6,997 weekdays (6998 including both ends); 2,800 weekend days; 9,798 days inclusive. the millennium so far — January 1, 2000 to October 28, 2026 is 9,797 days, 321 months and 27 days.
• A weekend: A weekend: From Saturday, October 24, 2026 to Monday, October 26, 2026: 2 days; 0 weeks and 2 days; 0 months 2 days; 48 hours; 2,880 minutes; 0 weekdays (1 including both ends); 2 weekend days; 3 days inclusive. a weekend — Saturday, October 24 to Monday, October 26 is 2 days, 0 weekdays, 2 weekend days.
• Christmas to New Year: Christmas to New Year: From Thursday, December 25, 2025 to Thursday, January 1, 2026: 7 days; 1 week and 0 days; 0 months 7 days; 168 hours; 10,080 minutes; 5 weekdays (6 including both ends); 2 weekend days; 8 days inclusive. Christmas to New Year — December 25, 2025 to January 1, 2026 is 7 days, one whole week, 5 weekdays.
• A summer: A summer: From Monday, June 1, 2026 to Tuesday, September 15, 2026: 106 days; 15 weeks and 1 day; 3 months 14 days; 2,544 hours; 152,640 minutes; 76 weekdays (77 including both ends); 30 weekend days; 107 days inclusive. a summer — June 1 to September 15, 2026 is 106 days, 15 weeks and 1 day.

The reverses, worked backwards

• Smallest end date for at least 300 days: October 28, 2026 — at October 28, 2026 the figures are From Thursday, January 1, 2026 to Wednesday, October 28, 2026: 300 days; 42 weeks and 6 days; 9 months 27 days; 7,200 hours; 432,000 minutes; 214 weekdays (215 including both ends); 86 weekend days; 301 days inclusive (unrounded 42.857143 weeks); at the earlier neighbor the figures are From Thursday, January 1, 2026 to Tuesday, October 27, 2026: 299 days; 42 weeks and 5 days; 9 months 26 days; 7,176 hours; 430,560 minutes; 213 weekdays (214 including both ends); 86 weekend days; 300 days inclusive (unrounded 42.714286 weeks); at the lower neighbor the figures are From Thursday, January 1, 2026 to Thursday, October 29, 2026: 301 days; 43 weeks and 0 days; 9 months 28 days; 7,224 hours; 433,440 minutes; 215 weekdays (216 including both ends); 86 weekend days; 302 days inclusive (unrounded 43.000000 weeks) — verdict: STEP.
• Largest start date for at least 100 days: July 20, 2026 — at July 20, 2026 the figures are From Monday, July 20, 2026 to Wednesday, October 28, 2026: 100 days; 14 weeks and 2 days; 3 months 8 days; 2,400 hours; 144,000 minutes; 72 weekdays (73 including both ends); 28 weekend days; 101 days inclusive (unrounded 14.285714 weeks); at the later neighbor the figures are From Tuesday, July 21, 2026 to Wednesday, October 28, 2026: 99 days; 14 weeks and 1 day; 3 months 7 days; 2,376 hours; 142,560 minutes; 71 weekdays (72 including both ends); 28 weekend days; 100 days inclusive (unrounded 14.142857 weeks); at the lower neighbor the figures are From Sunday, July 19, 2026 to Wednesday, October 28, 2026: 101 days; 14 weeks and 3 days; 3 months 9 days; 2,424 hours; 145,440 minutes; 72 weekdays (73 including both ends); 29 weekend days; 102 days inclusive (unrounded 14.428571 weeks) — verdict: STEP.
• Smallest number of days to add for the result to reach at least April 1, 2026: 90 days — at 90 days the figures are Thursday, January 1, 2026 + 90 days = Wednesday, April 1, 2026 (result 2026-04-01); at the lower neighbor the figures are Thursday, January 1, 2026 + 89 days = Tuesday, March 31, 2026 (result 2026-03-31); at the upper neighbor the figures are Thursday, January 1, 2026 + 91 days = Thursday, April 2, 2026 (result 2026-04-02) — verdict: STEP.
• Largest number of days to subtract for the result to stay on or after October 1, 2026: 27 days — at 27 days the figures are Wednesday, October 28, 2026 − 27 days = Thursday, October 1, 2026 (result 2026-10-01); at the upper neighbor the figures are Wednesday, October 28, 2026 − 28 days = Wednesday, September 30, 2026 (result 2026-09-30); at the lower neighbor the figures are Wednesday, October 28, 2026 − 26 days = Friday, October 2, 2026 (result 2026-10-02) — verdict: STEP.
• Smallest end date for at least 200 weekdays: October 8, 2026 — at October 8, 2026 the figures are From Thursday, January 1, 2026 to Thursday, October 8, 2026: 280 days; 40 weeks and 0 days; 9 months 7 days; 6,720 hours; 403,200 minutes; 200 weekdays (201 including both ends); 80 weekend days; 281 days inclusive (unrounded 40.000000 weeks); at the earlier neighbor the figures are From Thursday, January 1, 2026 to Wednesday, October 7, 2026: 279 days; 39 weeks and 6 days; 9 months 6 days; 6,696 hours; 401,760 minutes; 199 weekdays (200 including both ends); 80 weekend days; 280 days inclusive (unrounded 39.857143 weeks); at the lower neighbor the figures are From Thursday, January 1, 2026 to Friday, October 9, 2026: 281 days; 40 weeks and 1 day; 9 months 8 days; 6,744 hours; 404,640 minutes; 201 weekdays (202 including both ends); 80 weekend days; 282 days inclusive (unrounded 40.142857 weeks) — verdict: STEP.
• Largest start date for at most 10 weekend days: September 21, 2026 — at September 21, 2026 the figures are From Monday, September 21, 2026 to Wednesday, October 28, 2026: 37 days; 5 weeks and 2 days; 1 month 7 days; 888 hours; 53,280 minutes; 27 weekdays (28 including both ends); 10 weekend days; 38 days inclusive (unrounded 5.285714 weeks); at the earlier neighbor the figures are From Sunday, September 20, 2026 to Wednesday, October 28, 2026: 38 days; 5 weeks and 3 days; 1 month 8 days; 912 hours; 54,720 minutes; 27 weekdays (28 including both ends); 11 weekend days; 39 days inclusive (unrounded 5.428571 weeks); at the lower neighbor the figures are From Tuesday, September 22, 2026 to Wednesday, October 28, 2026: 36 days; 5 weeks and 1 day; 1 month 6 days; 864 hours; 51,840 minutes; 26 weekdays (27 including both ends); 10 weekend days; 37 days inclusive (unrounded 5.142857 weeks) — verdict: STEP.

What the defaults assume

The defaults are January 1 to October 28, 2026 — the year so far, from New Year's Day to today — and the span is 300 days, 42 weeks and 6 days, 9 months 27 days. They are a starting point, not a benchmark: your dates may be a weekend, a leap year or a century apart, and the right answer for you is the one your dates describe. Change the start date, the end date and the days to add to your own and the calculator recomputes instantly. Take the two midnights, subtract, and count what falls in between.

These notes repeat in every explainer section because this page is built to be read start to finish: the defaults are one span, not a standard; days, weeks and months are three different counts; months follow the calendar, not 30 days; and inclusive and exclusive are different answers.

Output · formula · meaning

Who uses this

• A project manager counting a deadline — January 1 to October 28, 2026 is 300 days, 214 weekdays, and the workdays are the number the plan runs on.
• A traveller working out a trip — Saturday, October 24 to Monday, October 26 is 2 days, 0 weekdays, 2 weekend days, a weekend away.
• A parent counting down to a due date or a birthday — January 1 plus 100 days is Saturday, April 11, 2026, and the weekday is part of the answer.
• Anyone checking a date — the smallest end date for at least 200 weekdays from January 1 is October 8, 2026, and October 7 is 199, so one day matters.

Accuracy & limitations

The calculator counts in whole days on the Gregorian calendar, in UTC, so no time zone ever moves a date by a day — every span on this page is checked against an independent model, and the weekdays are counted in the span itself, not estimated. What it cannot do is count holidays: the weekdays figure counts Monday to Friday, and a public holiday is still a weekday here, so a business-days count needs the business-days-calculator page. It also counts calendar months by the same-day rule, with the day clamped where the month is shorter — January 31 plus one month is February 28 — which is the usual convention, not the only one. And the page prints the unrounded weeks so the rounding does not mislead you — 300 days is 42.857143 weeks, not 42.86.

Cite this calculator

The days between two dates are the difference of the two midnights. On the defaults — January 1 to October 28, 2026 — the span is 300 days, 42 weeks and 6 days, 9 months 27 days, 7,200 hours, 432,000 minutes, 214 weekdays and 86 weekend days. Smallest end date for at least 300 days: October 28, 2026. Largest start date for at least 100 days: July 20, 2026. Smallest number of days to add for the result to reach at least April 1, 2026: 90 days. Largest number of days to subtract for the result to stay on or after October 1, 2026: 27 days. Smallest end date for at least 200 weekdays: October 8, 2026. Largest start date for at most 10 weekend days: September 21, 2026. Source: Bright Side Kit, brightoolbox.com.

Frequently asked questions