Date Calculator
Find days between two dates, or add & subtract days from any date — free & instant
What is this Date Calculator?
This free date calculator performs two types of date arithmetic instantly — no manual counting on a calendar required. The Date Difference tab tells you exactly how many days lie between any two dates: past, present, or future. The Add / Subtract Days tab takes any base date and adds or subtracts any number of days to give you the resulting date — including the full day name (Monday, Tuesday, etc.) so you can immediately see whether a deadline falls on a weekday or weekend.
Both modes handle leap years automatically, including the century-year rule (years divisible by 100 are not leap years unless also divisible by 400 — so 1900 was not a leap year, but 2000 was). The calculator works for any date in the Gregorian calendar from October 1582 onwards — covering historical research, ancient date comparisons, and any practical future planning through the far future. All calculations run entirely in your browser; no dates you enter are stored or transmitted anywhere.
How to use — step by step
- Date Difference tab: Select a start date and an end date using the date pickers (or type dates directly). Click Calculate — or press Enter. The result shows the total number of calendar days between the two dates, with both dates displayed in full (e.g. "Monday, 1 January 2024 → Friday, 31 March 2024"). If you accidentally enter the end date before the start date, the calculator swaps them and notes it in the result — you always get a positive count.
- Add / Subtract Days tab: Enter a base date (defaults to today). Enter the number of days to add — use a positive number to go forward in time (e.g. 90) or a negative number to go back (e.g. -30). Click Calculate — the result shows the resulting full date including the day of the week. This is the mode to use for "what date is 45 days from today?" or "what date was 60 days ago?"
- Both modes: The result displays a large number at the top and a plain-language note below. The date display uses the format "Day name, Date Month Year" — this is intentional so you immediately know whether the result lands on a weekend or weekday without needing to check a separate calendar.
Key features
- Two calculation modes: Date difference (days between two dates) and date offset (add/subtract days from a date)
- Full day name in result: Shows "Monday", "Tuesday" etc. so you can immediately check for weekends
- Complete leap year handling: Includes the century-year exception (1900 ≠ leap year, 2000 = leap year)
- Negative day subtraction: Enter a negative number in the Add/Subtract tab to go backward in time
- Gregorian calendar coverage: Works for any date from October 1582 to far future
- Enter key support: Press Enter to calculate without clicking the button
- Pre-filled defaults: Start date = today, End date = today + 30 days — so you can see a result immediately on page load
Date calculations in India — financial year, legal deadlines, GST, and more
India runs on a financial year from 1 April to 31 March — which means many of the most important date calculations for Indians involve counting days from or to key dates in that cycle. Here are the most common use cases and how to handle each one with this calculator.
Indian financial year and tax deadlines
ITR filing deadlines
ITR for individuals is due 31 July. Use the Date Difference tab to find how many days you have left: start = today, end = 31 July of the current financial year. For belated return (with penalty): the extended deadline is typically 31 December. Missed that? Use Add/Subtract to check if updated return (ITR-U) is still possible — you have up to 2 years from the end of the relevant assessment year.
GST return due dates
GSTR-1 (outward supplies): 11th of the following month for monthly filers; quarterly filers — 13th of the month after the quarter end. GSTR-3B: 20th of the following month. Use Add/Subtract tab: base date = last day of the month, add 11 or 20 days to confirm the exact filing due date. Late filing attracts ₹50/day penalty (₹20/day for Nil returns).
TDS deposit deadlines
TDS deducted in any month must be deposited by the 7th of the following month (except March deductions — due 30 April). Use Add/Subtract: base date = last day of the month, add 7 days to find the TDS deposit deadline. Late deposit: interest at 1.5% per month from deduction date to payment date under Section 201(1A).
"X days from today" — quick reference for common planning horizons
These are the most frequently searched date offsets. Use the Add / Subtract Days tab with today's date and the number below to find the exact date. Day names are shown in the result so you can check if it falls on a weekend:
- 30 days from today: Standard notice period in most Indian employment contracts. Also: credit card billing cycle, monthly rental advance deadline, RBI moratorium periods.
- 45 days from today: MSME payment deadline under the MSMED Act — buyers must pay MSMEs within 45 days of acceptance of goods/services or face interest at 3× bank rate. Also: many government tender submission timelines.
- 60 days from today: Standard project milestone window. Also: period within which a cheque bounce case must be filed after receiving the legal notice (Section 138 of Negotiable Instruments Act — the 15-day reply window + 30-day further window).
- 90 days from today: Quarter-end planning (most Indian companies operate on April-June, July-September, October-December, January-March quarters). Also: typical bank loan EMI overdue threshold before NPA classification begins.
- 180 days from today: Six-month project planning. Also: the period within which an export bill must be realised in India (FEMA regulations). Also: SEBI's timeline for many regulatory responses.
- 365 days from today: One year from today — useful for anniversary dates, annual contract renewals, insurance policy renewals, and fixed deposit maturity dates.
Legal and court timelines in India
Indian courts and legal procedures are heavily date-dependent. The Limitation Act, 1963 governs deadlines for filing suits, appeals, and applications — and most periods are specified in calendar days, not working days. Key examples:
- Filing a civil suit: 3 years from the date the cause of action arose (for most money recovery suits). Count back 3 years from today to see if a cause of action is still within the limitation period: Date Difference tab, start = date of cause of action, end = today — if the result exceeds 1095 days (3 × 365), the limitation may have expired.
- Cheque bounce (Section 138, NI Act): After the cheque is dishonoured, the payee sends a legal notice. The drawer has 15 days to pay. If they don't, the payee has 30 more days to file the complaint. Use Add/Subtract to track each of these windows from the dishonour date.
- Consumer forum: A consumer complaint must typically be filed within 2 years of the deficiency in service. Check this with the Date Difference tab — if days between the service deficiency date and today exceed 730 (2 × 365), the window may have closed (subject to court discretion on delay condonation).
- Arbitration award challenge: An arbitration award can be challenged in court within 3 months of its receipt (Section 34, Arbitration Act). Use Add/Subtract: base date = award receipt date, add 90 days to find the challenge deadline.
Pregnancy and health date calculations
A standard pregnancy (Naegele's rule) lasts 280 days (40 weeks) from the first day of the last menstrual period (LMP). To calculate your estimated due date: switch to the Add / Subtract Days tab, enter the LMP date as the base date, and enter 280 days. The result is the estimated due date. This matches what most doctors calculate, though actual delivery typically occurs between 259 days (37 weeks) and 294 days (42 weeks).
Other useful health-related date calculations: vaccination schedules (e.g. second dose 28 days after first dose — enter vaccination date + 28), medication course end dates, fasting blood test appointment planning, and post-surgery recovery milestones.
How leap years affect date calculations
A leap year adds one extra day (February 29) — which means any date calculation spanning a leap year's February will be off by 1 day if the leap year is not accounted for. The rules are: A year is a leap year if: (1) It is divisible by 4 — AND (2) It is NOT a century year (divisible by 100) — UNLESS (3) It IS divisible by 400. So: 2024 = leap year (divisible by 4, not a century year). 1900 = NOT a leap year (century year, not divisible by 400). 2000 = leap year (divisible by 400). This calculator handles all three rules correctly. For multi-year calculations — e.g. "how many days between 1 January 2020 and 1 January 2025?" — the answer is 1827 days (not 1825), because 2020 and 2024 were both leap years, adding 2 extra days. The calculator gives the correct answer of 1827 instantly.
Instant, leap-year accurate, works for any date from 1582.
Frequently asked questions
How do I find the number of days between two dates?
Click the Date Difference tab (it is selected by default). Enter your start date using the first date picker and your end date using the second date picker — or type the dates directly in YYYY-MM-DD format. Click Calculate or press Enter. The result appears immediately showing the total calendar days between the two dates, with both dates written out in full (e.g. "Monday, 1 April 2024 → Wednesday, 31 July 2024"). Example: start = 1 April 2024, end = 31 July 2024 → 121 days (the Q1 of India's financial year). Note: both the start and end dates themselves are included in the count — or to be precise, the calculator counts the absolute difference in days between the two calendar dates. If you enter the same date twice, the result is 0 days.
How do I calculate what date falls 30, 45, 60, or 90 days from today?
Click the Add / Subtract Days tab. The base date field will already show today's date. In the "Days to add" field, type the number of days you want to count forward: 30, 45, 60, 90, or any other number. Click Calculate or press Enter. The result shows the exact future date in full format, including the day name — so you can immediately see if it lands on a Saturday or Sunday. Examples using today as 19 July 2025: +30 days = Monday, 18 August 2025. +45 days = Tuesday, 2 September 2025. +60 days = Sunday, 17 September 2025 (a weekend — if this is a legal deadline, you may need to check if the next working day applies). +90 days = Saturday, 18 October 2025. +180 days = Saturday, 14 January 2026. Knowing the day name lets you immediately identify deadline conflicts with weekends or public holidays.
How do I subtract days from a date — go back in time?
In the Add / Subtract Days tab, enter your base date, and type a negative number in the days field. Example: to find what date was 60 days before 31 March 2025, enter base date = 31 March 2025, days = -60. Result: Sunday, 30 January 2025. This is useful for: calculating when a statute of limitations started running (count back from today), finding the invoice date that a payment should reference (count back from payment due date), confirming whether an advance notice was given in time (count back from the deadline date to verify the notice date), and calculating start dates for probationary periods or subscription terms working backward from the end date.
Does this calculator count calendar days or business days?
This calculator counts calendar days only — every day including Saturdays, Sundays, and public holidays is counted. It does not have a built-in business-days-only mode. This means: the difference between 1 July 2025 (Tuesday) and 31 July 2025 (Thursday) is 30 calendar days, which includes approximately 8 weekend days (so roughly 22 business days). For Indian legal and financial deadlines, it is important to know which type of day count applies. Most Indian laws (Limitation Act, NI Act, GST deadlines) specify calendar days — use this calculator directly. However, some court orders, SEBI regulations, and HR policies specify working days — in those cases, you will need to manually subtract weekends and public holidays from the result this calculator gives. A rough formula: business days ≈ calendar days × (5/7) — but this varies with public holidays in your state.
How accurate is this calculator for historical dates and leap years?
Completely accurate for any date in the Gregorian calendar from October 15, 1582 onwards. The calculator uses JavaScript's native Date object, which correctly applies all three leap year rules: divisible by 4 = leap year; divisible by 100 = NOT a leap year (century rule exception); divisible by 400 = IS a leap year (override). This means: 2024 ✓ leap year. 2100 ✗ not a leap year (century year, not divisible by 400). 2000 ✓ leap year (divisible by 400). For multi-decade calculations, this matters: the interval from 1 March 1900 to 1 March 2000 is exactly 36,524 days — not 36,525 — because 1900 was not a leap year (a common mistake that adds an extra day). This calculator gives the correct 36,524. Important: dates before October 15, 1582 do not exist in the Gregorian calendar (the Julian calendar was used before that date, and the two systems differ by 10+ days). For historical research involving pre-1582 dates, note that different countries adopted the Gregorian calendar at different times — England in 1752, Russia in 1918.
What are common date calculations for Indian financial and legal planning?
Income Tax: ITR due date = 31 July. Days remaining: Date Difference tab, start = today, end = 31 July. TDS deposit due: Add/Subtract, base = last day of deduction month, add 7 (add 30 for March deductions, giving 30 April). GST: GSTR-1 due: base = last day of month, add 11. GSTR-3B due: base = last day of month, add 20. MSME payments: base = invoice acceptance date, add 45. If payment is overdue, Date Difference tab shows how many days of interest liability has accumulated. Fixed deposits: base = FD start date, add the number of days of tenure (e.g. 365 for 1-year FD, 366 if a leap year falls in the tenure) to find exact maturity date and day name. Loan EMI dates: base = disbursement date, add 30 for first EMI date — repeat as needed. Notice period: base = resignation date, add 30, 60, or 90 days per your contract to find last working day. Cheque bounce: base = dishonour date, add 15 (legal notice reply window), add 30 more (complaint filing window). Passport validity: Many countries require 6 months validity — base = travel date, subtract 180 to find the minimum passport expiry date that is acceptable.
Can I use this to calculate my age in days, weeks, or years?
Yes — for age in calendar days: use the Date Difference tab, enter your date of birth as the start date and today as the end date. Example: born 15 August 1990, calculating on 19 July 2025 → 12,756 days old. For a quick check: multiply years × 365 and add the days from leap years (roughly years ÷ 4). For weeks: take the days result and divide by 7 (e.g. 12,756 days ÷ 7 = 1,822 weeks). For years, months, and days broken down separately — for example "34 years, 11 months, 4 days" — use the dedicated Age Calculator on Toolwala, which provides that precise breakdown including handling of different month lengths. The Date Calculator gives the total elapsed days only, not the broken-down years-months-days format. The two tools complement each other — use this one when you need a raw day count, and the Age Calculator when you need the human-readable age format.