Almost every "date calculator" question people search for is really one of five distinct problems: how many days until something, how many weeks, how many actual working days, what does that weird number in a spreadsheet mean, or what time is it somewhere else right now. Most calculator sites bury all five behind one bloated, ad-heavy page — or worse, split them across separate tools that don't agree with each other. We built five focused, free tools instead, each doing exactly one job well, all running entirely in your browser with nothing uploaded or stored.
1. Counting the exact number of days between two dates
This is the most common date question of all: "how many days until my trip," "how many days has it been since I started this job," "how many days do I have left on this deadline." The days between dates calculator handles all of these instantly. Enter a start date and an end date and it shows the total day count, plus a weeks-and-days breakdown and an approximate month count — no submit button, no waiting.
It also supports two options most competitors skip: an "include the end date" toggle for inclusive counting (useful for rental periods or vacation days where both the arrival and departure day count), and an optional time-of-day mode for when you need the exact duration down to the hour and minute, not just whole days.
Free, instant, no signup
2. Measuring a gap in weeks, not days
Days aren't always the most useful unit. If you're tracking pregnancy progress, a training program, or a project sprint, you think in weeks. Oddly, almost no calculator site gives "weeks between dates" its own dedicated page — it's usually just one extra line buried inside a generic days-calculator result. The weeks between dates calculator makes weeks the main event: a clean whole-weeks-plus-leftover-days figure ("8 weeks, 3 days") alongside a precise decimal value ("8.4 weeks") for when you need more granularity.
3. Counting actual working days (not weekends, not holidays)
"Days between dates" and "business days between dates" are very different numbers, and mixing them up causes real problems — missed contract deadlines, wrong delivery-date promises, payroll errors. The business days calculator counts only Monday-through-Friday dates in your range, with US federal holidays excluded automatically by default (all 11 of them, calculated correctly per year, including floating holidays like "third Monday of January" and weekend-observed shifting rules). You can turn that off, or add your own custom holidays and company shutdown days — one per line — and even export the resulting business-day list as a CSV.
Most competing tools force you through a country picker before you can get a simple US answer. This one defaults straight to US federal holidays with a single checkbox, because that's what the majority of searchers actually need.
US holidays built in, free
4. Decoding a Unix timestamp
If you've ever opened a log file, a database export, or an API response and seen a number like 1774032000 sitting where a date should be, that's a Unix (epoch) timestamp — a count of seconds, or sometimes milliseconds, since January 1, 1970. The Unix timestamp converter turns that number back into a readable date in both UTC and your local time zone, and works the other direction too: pick a date and get the matching timestamp in seconds or milliseconds. It auto-detects whether you've pasted a 10-digit seconds value or a 13-digit milliseconds value, so you don't need to know the difference going in — it also displays a live "current timestamp" so you can see exactly what one looks like right now.
5. Converting a time across time zones
"What time is 3pm EST in London" is one of the highest-friction searches on the web — most tools that answer it also want you to sign up, install an app, or squint at a dense hover-grid on your phone. The time zone converter is two dropdowns and a date/time field: pick a "from" zone, pick a "to" zone, and get an instant, Daylight-Saving-Time-aware answer, with quick-pick shortcuts for common pairs like EST↔PST, UTC↔EST, and IST↔EST. Because it uses your browser's real timezone database instead of a fixed offset, the same conversion done in July and in January will each correctly reflect DST in both zones — a fixed "add 3 hours" rule can't do that.
Why these are free, and why they don't ask for your email
Every calculation on all five tools happens with plain JavaScript running in your own browser tab. There's no server processing your dates, no account required to unlock a result, and no watermark or usage cap. Close the tab and everything is gone — nothing is stored or logged by IT Cares. That's a genuinely different approach from most "free" calculator sites, which usually monetize with ads, affiliate links, or an eventual account paywall.
Frequently asked questions
Which calculator should I use to count vacation or rental days?
Use the days between dates calculator with "count the end date as a full day" checked, so both your arrival and departure day are included in the total.
Which calculator should I use for a contract deadline that says "business days"?
Use the business days calculator — "business days" and "calendar days" are different numbers, and using the wrong one is a common way to miss a real deadline.
Do I need to know anything technical to use the timestamp converter?
No. The Unix timestamp converter is built for non-developers too — paste the number you're stuck on and it explains the date in plain language, no coding background needed.
Are any of these tools going to ask me to sign up eventually?
No. All five tools, and every free tool on this site, are permanently free with no account, no email capture, and no usage limits.