📅Date Difference Calculator
Count the total days between two dates, plus the breakdown in weeks and days and in calendar years, months and days.
Worked examples
2024-01-01 → 2024-12-31
GET /api/v1/calculators/date-difference-calculator?start=2024-01-01&end=2024-12-31
Result: 365 days
2020-02-28 → 2020-03-01 (leap year)
GET /api/v1/calculators/date-difference-calculator?start=2020-02-28&end=2020-03-01
Result: 2 days
1990-06-15 → 2026-09-01
GET /api/v1/calculators/date-difference-calculator?start=1990-06-15&end=2026-09-01
Result: 13,227 days
Machine API (x402)
$0.001 / callThis tool is also a JSON API for AI agents. Requests without payment receive 402 Payment Required plus instructions; agents pay USDC on Base via the x402 protocol — no accounts, no API keys.
GET /api/v1/calculators/date-difference-calculator?start=2024-01-01&end=2024-12-31 HTTP/1.1
Host: agenttools-hub.vercel.app
→ 402 (payment required, instructions in headers)
→ 200 (after X-PAYMENT header; JSON body below)
{
"tool": "calculators/date-difference-calculator",
"input": {"start":"2024-01-01","end":"2024-12-31"},
"result": { "value": 365, "answer": "365 days" }
}Agent docs: /llms.txt · OpenAPI spec · integration guide
About this tool
Enter two ISO dates (YYYY-MM-DD) to get the exact number of days between them, the weeks-and-days breakdown, the calendar years/months/days split, and total hours.
total days = (end UTC midnight − start UTC midnight) ÷ 86,400 seconds
Frequently asked questions
Does the count include both end days?
The result is the difference between the two dates (end minus start). Add 1 to include both the first and the last day in a count.
How are leap years handled?
The calculation uses real calendar arithmetic on UTC timestamps, so Feb 29 is counted exactly as it occurs.
Are time zones considered?
Both dates are interpreted as midnight UTC, so results are independent of your local time zone.