Weekday count in a year
Pick a weekday and a year to see how many times that day occurs: 2024 has 53 Mondays, because it is a leap year that starts on a Monday. Most weekdays occur 52 times, while one or two reach 53. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Year
- 2,024
- Weekday
- Monday
- Weekday index
- 1
- Quantity
- 53
- Days in year
- 366
- Jan1 weekday
- 1
Planning meetings, payroll cycles, content calendars, and classroom date drills all run into the same question: how many times does a given weekday fall inside a particular year? A common year has three hundred sixty-five days, so fifty-two full weeks plus one leftover day; a leap year has three hundred sixty-six, so two leftover days. Those leftovers mean most weekdays appear fifty-two times while one or two weekdays appear fifty-three times, depending on which day of the week January first lands on and whether February twenty-ninth exists. Unrecognized weekday strings fail with a clear invalid input error and are not charged.
How weekday frequency works in common and leap years
Every Gregorian year contains either three hundred sixty-five or three hundred sixty-six days. Three hundred sixty-five equals fifty-two weeks plus one day, so exactly one weekday appears fifty-three times and the other six appear fifty-two times. Three hundred sixty-six equals fifty-two weeks plus two days, so two consecutive weekdays appear fifty-three times—the weekday of January first and the next weekday in the week.
Leap years follow the standard rule: divisible by four, except century years unless divisible by four hundred. Send weekday as a full English name such as Monday, a three-letter abbreviation such as Mon, or an integer from zero through six where zero is Sunday. Case is ignored for names.
What you can do with it
Meeting and campaign calendars
Product and marketing teams check how many Mondays or Fridays fall in a launch year before booking recurring slots or weekly content drops.
Payroll and shift estimators
HR and ops tools estimate weekly pay cycles or shift templates from the true weekday frequency in a common or leap year.
FAQ
How do I count how many Mondays are in a year?
The count field is 52 or 53 depending on that Gregorian year.
What happens if the weekday name is wrong?
Unrecognized names such as "Funday" are rejected and not charged; use Sunday–Saturday or common three-letter abbreviations.
Does leap year change the answer?
Yes. A leap year has 366 days, so two weekdays appear 53 times instead of one. February 29 is included via the standard Gregorian leap rule.
Is the weekday count calculator free?
The browser tool runs free on your device.
Can I pass a number instead of a name?
Yes. Weekday may be an integer 0–6 where 0 is Sunday and 6 is Saturday, matching common calendar APIs. The response still returns the canonical English name.
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/weekday-frequency \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"year":2024,"weekday":"Monday"}'const res = await fetch("https://api.kit.forhosting.com/date/weekday-frequency", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"year": 2024,
"weekday": "Monday"
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/date/weekday-frequency",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"year": 2024,
"weekday": "Monday"
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/date/weekday-frequency", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"year":2024,"weekday":"Monday"}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"year":2024,"weekday":"Monday"}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/date/weekday-frequency", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"year": 2024,
"weekday": "Monday"
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "date.weekday_frequency",
"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.
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
How weekday frequency works in common and leap years
Send year as a JSON integer or integer string (aliases y and yr). Identical inputs always produce identical JSON because the path is pure arithmetic with no network, no random seed, and no wall clock.
Reading the response fields and handling invalid weekday names
The count field is the answer you came for: fifty-two or fifty-three. The error message names the bad token when possible so forms can show a precise hint. Prefer full names in user-facing forms; accept abbreviations and numeric indices when integrating calendars that already use zero-based Sunday indices. On success the response echoes year, the canonical weekday name (Sunday through Saturday), and weekday_index from zero for Sunday through six for Saturday. Supporting fields help UIs and tests: days_in_year is three hundred sixty-five or three hundred sixty-six, is_leap_year is a boolean, jan1_weekday and jan1_weekday_name describe the first day of the year, and weekdays_with_53 lists every weekday name that appears fifty-three times that year so you can highlight the long weekdays without a second request. The method label is always weekday_frequency and calendar is always gregorian so downstream code can branch without sniffing shapes. Missing year, missing weekday, year outside one to nine thousand nine hundred ninety-nine, non-integer year, and any unrecognized weekday string all fail with invalid_input and are not charged.
API usage, pricing, scheduling workflows, and practical limits
Call the free in-browser weekday count calculator for meeting planners, editorial calendars, school timetables, and quick checks of how many Fridays or Mondays a campaign year contains. Years are limited to one through nine thousand nine hundred ninety-nine to match other date tools in the catalog and keep display safe. Send a JSON body with the required integer year and the required string or integer weekday. Use the prepaid API when a scheduling service, payroll estimator, content CMS, or calendar analytics pipeline needs a stable contract under KIT balance at $0.002 per successful item; validation failures never consume balance after the engine rejects the request. Pair this endpoint with a month calendar generator when you need a printable grid, or with business-day counters when holidays matter more than raw weekday frequency. Authors shipping SDKs can map count and weekdays_with_53 directly into dashboards that answer how many Mondays in a year without reimplementing leap rules in every language.
Integration use cases
Classroom and quiz generators
Teachers and tutoring apps ask how many Tuesdays are in a year and verify student answers with deterministic JSON.