A days since calculator counts the number of days between a past date and today. You pick a start date, the tool turns both dates into day numbers, subtracts them and shows the gap in days, weeks, months, hours and working days. The count moves forward at your own midnight, so the number is right every time you come back.
The calculator gives you 3 main benefits: exact counts across leap years and uneven month lengths, instant answers without spreadsheet math, and breakdowns you can use straight away, such as weeks for a pregnancy timeline or working days for an invoice.
People use a days since calculator for 4 main jobs: personal milestones like anniversaries and birthdays, streak tracking for habits and sobriety, maintenance logs like the days since last oil change, and historical date tracking for events like Inauguration Day on January 20, 2025.
How to Use the Days Since Calculator
To use the days since calculator, enter a start date, leave the end date on today and press Calculate days. The full count appears in the Results section in under a second.
- 1Pick the modeChoose Days Since for a past date or Days Until for a countdown to a future date.
- 2Enter the From dateType the date or pick it from the calendar. For an age in days, enter the date of birth.
- 3Check the To dateThe To date starts on today. Change it to count the days between two past dates.
- 4Set the optionsTurn on Include the end day, or open More options for weeks, months, working days and holidays.
- 5Press Calculate daysThe page scrolls to your result and keeps the count in History for later.
How Many Days Has It Been Since…?
Here are the live counts for the dates people search most, counted to today, Thursday, October 29, 2026.
Inauguration Day 2025 was the coldest inauguration in 40 years. The swearing-in on January 20, 2025 moved indoors to the Capitol Rotunda, the first indoor ceremony since Ronald Reagan's second inauguration in 1985, when the noon temperature was 7°F (−14°C). The count passed 565 days on August 8, 2026 and stands at 647 days today. Inauguration comparisons like this one are a common use of historical date tracking.
How Are the Days Since a Date Calculated?
The days since a date are calculated by subtracting the start date from the end date. The calculator converts both dates into day numbers counted from a fixed point, then takes the difference. The result matches the calendar arithmetic used by the Timeanddate.com Date Calculator from Time and Date AS, Calculator.net, Omni Calculator and Wolfram Alpha.
Day numbers here count from January 1, 1970, the Unix epoch. Today is day 20,755 of Unix time.
Fix the two ends
Every count needs a start and an end. The start day itself is never counted.
Count each midnight crossed
Each square that lights up is one midnight passed. That is one day.
Split it into weeks and workdays
43 weeks · 215 weekdays and 86 weekend days.
Read the answer
Thursday, January 1, 2026 was 301 days ago.
The start date is not counted and the end date is. Monday to Wednesday is 2 days. Turn on Include the end day to count both dates and get 3.
- ÷ 4 leap year 2024 ✓
- ÷ 100 not a leap year 1900 ✗
- ÷ 400 leap year again 2000 ✓
Dates are read in your device's time zone, so the count changes at your local midnight. Daylight saving time moves clock hours, not dates, and leaves the day count unchanged.
Counting days in Excel, Google Sheets and code
Spreadsheets store dates as serial day numbers, so a subtraction gives days elapsed. The DATEDIF function in Excel and Google Sheets returns the same count with the "d" unit. Programmers use the same idea with the Julian Day Number (JDN), Unix epoch time and dates in ISO 8601 date format (YYYY-MM-DD). The JavaScript Date object, the Python datetime module, Moment.js and Day.js all subtract two dates to get elapsed time.
=TODAY()-A2
=DATEDIF(A2, TODAY(), "d")
=NETWORKDAYS(A2, TODAY())const start = Date.UTC(2026, 0, 1);
const end = Date.UTC(2026, 9, 29);
(end - start) / 86400000; // 301from datetime import date
(date.today() - date(2026, 1, 1)).days
# 301dayjs().diff("2026-01-01", "day");
// 301What Can You Count With a Days Since Calculator?
You can count 6 kinds of dates with a days since calculator: personal milestones, habit and recovery streaks, home and car maintenance, health check-ups, work and compliance tasks, and historical events.
Anniversaries, birthdays and life events. Enter a date of birth to see your age in days.
Streak tracking keeps progress visible. Enter the day a streak started to see the days, weeks and next milestone.
Service intervals are easier to keep when the gap is a number, not a guess.
Appointments and cycles that repeat every few weeks or months.
Project management and milestone tracking need exact numbers for reports and audits.
Date comparison for research, trivia and data work, from world events to the Unix epoch.
How Many Days Are in a Week, Month and Year?
A week has 7 days, a month has 28 to 31 days, and a year has 365 days, or 366 days in a leap year. 2026 has 365 days; today is day 302.
7 months have 31 days, 4 months have 30 days and February has 28 days, or 29 days in a leap year. A quarter has 90 to 92 days, a decade 3,652 or 3,653 days and a century 36,524 or 36,525 days.
| Days | Weeks | Months | Years |
|---|---|---|---|
| 7 | 1 week | 0.2 | 0.02 |
| 30 | 4 weeks + 2 days | 1.0 | 0.08 |
| 90 | 12 weeks + 6 days | 3.0 | 0.25 |
| 100 | 14 weeks + 2 days | 3.3 | 0.27 |
| 180 | 25 weeks + 5 days | 5.9 | 0.49 |
| 365 | 52 weeks + 1 day | 12.0 | 1.00 |
| 500 | 71 weeks + 3 days | 16.4 | 1.37 |
| 1,000 | 142 weeks + 6 days | 32.9 | 2.74 |
| 10,000 | 1,428 weeks + 4 days | 328.5 | 27.38 |
Other Date and Time Calculators
DaysAtHand has 3 more date and time calculators, including a Days Between Dates Calculator, a Days Until countdown timer and a Days From Today calculator. The Days Between Dates Calculator works as a business day calculator, and the Days Since Calculator works as an age calculator or an anniversary calculator when you enter a birth date or a wedding date.
Date & Countdown Guides
Counting rules, holiday planners and worked examples you can check in the calculators above.
24 Christmas countdown activities for kids, one for each date from December 1 to 24, 2026, with supplies, time, cheaper swaps and a printable checklist.
Calendar days vs business days: calendar days count every date, business days skip weekends and holidays. See one week in November 2026 counted three ways.
Inclusive date counting counts every date from start to end, so January 1 to 3 is 3 days, not 2. See when to add one day, with checked examples and a table.
FAQs
How do I calculate how many days it has been since a date?
Enter the date in the From box, keep the To box on today and press Calculate days. The days since calculator subtracts the start date from today and shows the total in days, weeks, months, hours and working days. To count by hand, add the days left in the start month, the days in every full month after it and the days so far in the current month.
Does the calculator include the end date?
Yes, the calculator counts the end date and leaves out the start date. From June 1 to June 3 is 2 days. Turn on Include the end day to count both dates, which gives 3 days.
Are leap years counted?
Yes, every February 29 inside your date range is counted. A year is a leap year when it divides evenly by 4, except century years, which must divide evenly by 400. 2024 and 2028 are leap years; 1900 and 2100 are not.
How many days since January 1, 2026?
It has been 301 days since January 1, 2026, counting to today, Thursday, October 29, 2026. That is 43 weeks, or 9 months and 28 days.
Can I count only business days?
Yes. Open More options and set Show result in to Working days. The calculator skips Saturdays and Sundays by default, and you can change the weekend to Friday and Saturday, skip the 11 US federal holidays or add your own holiday dates.
What happens if I enter a future date?
The calculator shows how many days away the date is and offers a one-click switch to Days Until. In Days Until mode the same date becomes a countdown with weeks, weekends, business days and sleeps left.
How do I count days since a date in Excel?
Type =TODAY()-A2 with the start date in cell A2 and format the result cell as a number. =DATEDIF(A2,TODAY(),"d") returns the same number. For business days use =NETWORKDAYS(A2,TODAY()), which counts both the start and end dates. The same formulas work in Google Sheets.
Do time zones or daylight saving time affect the result?
No, time zones and daylight saving time (DST) do not change the day count. The calculator counts calendar dates in your device's time zone, so the number changes at your local midnight. DST only moves the clock by 1 hour on 2 days a year, and the hour totals use 24 hours per day.
Is the Days Since Calculator free?
Yes, the Days Since Calculator is free, with no sign-up and no usage limits. Your dates stay in your browser and are never sent to a server.
Count the days since any date
The DaysAtHand days since calculator shows how many days since any date, calculates the days between dates and switches to a countdown in one click, with weeks, months and working days for every count.