Add working days to a date
Add or subtract working days and skip every Saturday and Sunday: 5 working days after Monday 20 July 2026 is Monday 27 July 2026. The result names the weekday too, ready for a deadline or notice period. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Date
- 2026-07-20
- Working days to add
- 5
- Date
- 2026-07-27
- Base
- 2026-07-20
- Workdays
- 5
- Weekday
- Monday
Business deadlines almost never mean calendar days. When a contract says five working days from Monday, the due date is the following Monday, not Saturday. This capability takes a single ISO calendar date and an integer count of working days, then advances (or retreats) while skipping every Saturday and Sunday. The result is a precise ISO date plus the weekday name, so planners, SLA engines and invoice tools can trust the answer without opening a spreadsheet or guessing local timezone quirks.
What working days mean here
A working day is any Monday through Friday on the civil Gregorian calendar. Saturdays and Sundays are always skipped, whether you add days forward or subtract them backward. Public holidays are intentionally out of scope: they vary by country, region and industry, and baking a holiday table into a generic tool would silently wrong teams that use a different calendar.
If you need holiday-aware ranges, pair this result with your own holiday list or use a country-specific business-day counter. Zero leaves the base date unchanged even when that base falls on a weekend, which keeps reverse calculations honest. Negative counts walk backward with the same weekend rule, so one working day before a Monday is the previous Friday.
How to call it and read the result
Send two fields: date as a strict YYYY-MM-DD string, and days as an integer (positive, negative or zero). The absolute value of days is capped so a runaway loop cannot exhaust the isolate. Use the weekday fields in user-facing copy; use the ISO date as the system of record.
Because the algorithm never consults the local timezone, a date that is already midnight UTC in your pipeline stays a pure calendar value and does not slip by a day when a server runs in another zone.
Where it fits in real workflows
Operations teams use working-day offsets for delivery promises, support SLAs and contractual notice periods. Finance teams compute payment windows that exclude weekends. Product and marketing teams schedule launch gates, embargo lifts and content calendars without landing on Saturday.
The browser path is free for interactive checks: paste a start date, enter five, and confirm the landing day before you hard-code it. Combine the output with your own holiday tables when a region observes mid-week public holidays; this tool remains the reliable weekend filter underneath.
What you can do with it
SLA and support deadlines
Turn a ticket created on Thursday into a due date five working days later without landing on the weekend.
Contract and notice periods
Compute the last working day for notices, renewals and delivery windows from a signed ISO start date.
Payment and invoice windows
Add net working days to an invoice date so finance systems settle on weekdays only.
FAQ
What does it cost?
The same calculation runs free in your browser on this page.
Are public holidays skipped?
No. Only Saturdays and Sundays are skipped. Apply your own holiday list if a region needs it.
What happens if the base date is a weekend?
With days zero the weekend date is returned unchanged. With a positive or negative count the walk starts from that weekend and only stops on a weekday after the requested number of working days.
Can I subtract working days?
Yes. Pass a negative integer in days to move backward while still skipping weekends.
Why was my date rejected?
The date must be a real Gregorian calendar day in strict YYYY-MM-DD form.
Related tools
For developers — API access
Everything on this page is available programmatically. This section is for teams who want to wire it into their own systems; everyone else can just use the tool above.
API endpoint
Prefer to automate it? One authenticated POST creates the task; the result comes back by webhook or a signed link. The same capability also runs here on the web, by email and from Telegram — and soon from our app too.
Call it from your stack
curl -X POST https://api.kit.forhosting.com/date/add-workdays \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"date":"2026-07-20","days":5}'const res = await fetch("https://api.kit.forhosting.com/date/add-workdays", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"date": "2026-07-20",
"days": 5
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/date/add-workdays",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"date": "2026-07-20",
"days": 5
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/date/add-workdays", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"date":"2026-07-20","days":5}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"date":"2026-07-20","days":5}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/date/add-workdays", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"date": "2026-07-20",
"days": 5
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "date.add_workdays",
"status": "queued",
"_links": {
"result": "/tasks/tsk_…/result"
}
}The API is asynchronous: the call returns a task_id immediately and the result arrives by webhook. Polling is capped at 1 req/s per task.
Pricing
Published price — no tokens, no invented credits. A failed task is never charged.
Limits
max_workdays | 10000 |
Errors
| HTTP | Code | Meaning |
|---|---|---|
401 | unauthorized | Missing or invalid API key. |
402 | insufficient_balance | Your balance doesn't cover the task price. |
404 | unknown_type | That task type doesn't exist. |
429 | rate_limited | Too many requests. Use the webhook instead of polling. |
Technical notes
What working days mean here
The base date is the starting point and is not counted as one of the added days: from a Monday, adding one working day lands on Tuesday; from a Friday, adding one lands on the next Monday.
How to call it and read the result
Aliases such as base/start for the date and workdays/n/count for the integer are accepted so existing forms map cleanly. Invalid calendar dates fail immediately with invalid_input: 2026-02-30, 2026-13-01 and free-form strings are rejected rather than coerced. A successful response returns the resulting date, the original base, the signed workdays applied, the English weekday name, the ISO weekday number (Monday equals one through Sunday equals seven) and a boolean is_weekend flag that should always be false after a non-zero move that only stops on weekdays.
Where it fits in real workflows
Developers embed the same call in webhooks and CRON jobs so every service shares one definition of next business day instead of reimplementing ad-hoc loops that disagree on edge cases. The API path costs $0.002 per successful request and is billed per item, which keeps bulk planning scripts cheap while still covering edge execution.