Calculators · Group 03 of 08
Five precision instruments for the calendar and the clock — all running live in the box above. Pick a tool, choose your dates and watch every metric update instantly, right in your tab. Nothing is uploaded, nothing is stored.
Measures the span between any two dates in every unit that matters: total days, weeks, months, years, hours and minutes — plus how many of those days were working days (Mon–Fri) and how many fell on weekends. Leap years are handled automatically because the math runs on real calendar dates.
Jan 1, 2026 → Mar 1, 2026…
59 days · 8 weeks + 3 days · ≈ 2 months · 42 business days.
Use it for project timelinescontract durationsday countsanniversary math
Adds or subtracts a duration — hours, minutes and seconds — from any time of day. When the result crosses midnight it rolls over correctly and tells you the day shift (+1 or −1), and the duration itself is also shown as decimal hours, total minutes and total seconds.
23:30 + 1 h 45 m…
01:15 AM — next day (+1) · the same 1 h 45 m = 1.75 h = 105 min.
Use it for shift planningflight arrivalstime trackingscheduling calls
A genuine live countdown: pick any target date and time and the panel updates every second with the days, weeks, hours, minutes and seconds still to go. If the moment has already passed, it flips into counting how long ago it happened.
Target 45 days from now…
45 days to go — 1,080 hours · 64,800 minutes · ticking live.
Use it for launches & releasesweddingstrip departuresdeadlines
Moves forward or backward by working days only — Saturdays and Sundays are skipped automatically. It returns the landing date and day of week, the number of calendar days that actually elapsed, and how many weekend days were jumped over. Public holidays are country-specific, so they're not included.
Mon, Jan 5, 2026 + 10 business days…
Mon, Jan 19, 2026 — 14 calendar days, 2 weekends skipped.
Use it for delivery estimatesinvoice terms (Net 30)SLA windowsshipping dates
Enter two dates of birth and it computes both ages today, then the exact gap between them — years, months and days, with month-length borrowing done properly. It also names who is older, by how many days, and shows the combined and average age of the pair.
Person A: Apr 15, 1990 · Person B: Nov 2, 1993…
A is older by 3 y 6 m 18 d — exactly 1,297 days.
Use it for siblings & friendsteam age statsschool cohortsjust for fun
Conventions · difference = end − start, midnight to midnight · calendar month ≈ 30.44 days · business days = Mon–Fri (public holidays not included) · countdown updates every second · everything computed in your local time zone
This page has no backend and no database. Every number you just watched was computed by JavaScript inside your own browser tab — your dates and times never traveled a single centimeter of cable. Close the page and they're gone for good.
The difference is end date minus start date, counted from midnight to midnight. From Monday to the following Monday is 7 days. Hours are days × 24, minutes are days × 1,440, and calendar months are approximated at 30.44 days each. Leap years are exact, because the math runs on real calendar dates.
No. Business days exclude Saturdays and Sundays only, because public holidays differ by country and region. If a holiday falls inside your range, subtract one extra working day for each holiday.
No. IrisTool has no backend and no database. All calculations run inside your browser tab and disappear the moment you close or refresh the page. Your dates are never transmitted, stored or logged.
Yes. Once the page has loaded, every calculator keeps working offline, because all the math runs locally in your browser. The live countdown keeps ticking as well.