semku

Days until calculator

Choose a date to see right away how many days are left until it, or how many have passed since.

—
If you include the name, anyone who receives the link can see it. See the days left until the exam To count the first day as day 1, use the date calculator with “include the start date”.
How days are counted and saved

Days are counted from today in Korea Standard Time (KST). If the target date is tomorrow the result is D-1, yesterday D+1 and today D-day. After midnight KST the value changes with the KST date.

This is the difference in days up to the target date. Anniversary or service-day counts that treat the first day (for example the day you met or enlisted) as day 1 may use a different basis.

Saved entries keep the event name and the ISO date in this browser’s local storage. There is no server sync or backup. You can lose the list if you clear browser data, use another browser or device, or if the site address changes. If saving fails, one-off counting still works.

Frequently asked questions
Is the exam day itself included in the count?
The target date is D-day and the day before it is D-1. The exam day is not added as day 1. The result is the difference between today’s date and the target date on the KST calendar.
Why is the result one day more or less than on other calculators?
A countdown treats today as 0, but anniversary or service-day counts sometimes treat the start date as day 1. semku uses the rule: tomorrow is D-1, yesterday is D+1, today is D-day.
Can I see the remaining hours as well?
This page shows the countdown in whole days only. A countdown in hours, minutes and seconds is not supported.
Does the countdown show on my lock screen?
No. Save in this browser is a saved list on this page, not a lock-screen widget.
Can I save several dates with names?
Yes. Save a name and date for each event, then open or delete them from one list. The list is stored only on this device and in this browser, and is not synced to other devices.

Privacy on this page

Days are counted in your browser using the KST calendar date. The target date and event name you enter are not sent to the server. If you choose to save, the name and date are kept only in this browser’s local storage, with no server sync or backup. Opening a link that carries a date sends that date to the hosting server as part of the request URL; if you include the event name in a shared link, the name is sent too.

To understand how the page is used and to improve the service, this page sends semku’s own usage statistics and automatic error reports. They go only to the dedicated endpoint under semku.com/api/telemetry/v1/. They are not used for advertising or third-party tracking.

The usage statistics include the stage of use (such as starting an operation or requesting a copy), the time it happened and fixed identifiers that distinguish the page and feature. They do not include the target date or event name you enter, the saved list, the days shown or the links you copy. Inputs are not sent as hashes or as size categories either. The full URL and search terms are not sent.

Operations and sessions are distinguished by randomly generated identifiers. In the browser these exist only in temporary memory and are not written to cookies or browser storage. No identification based on cookies or combined device characteristics is used.

Error reports contain the error type, code and time, and, where available, a registered program-source identifier with the line and column number. The error message text and stack traces are not sent. Usage statistics and error reports also carry the site identifier, the published build and a random record identifier. IP addresses and user-agent strings are not part of these items.

The feedback form sends the rating you chose and the text you typed in the free-text field when you press the send button. A random ID that distinguishes the submission, the page, site and published build, and the type of request are also sent. There are no fields for your name, email address or phone number, and the dates or names you enter are not attached automatically. Whatever you write in the free-text field is sent as is. Please do not enter personal data, passwords, authentication keys or payment details.

Separately, when you visit the site, the hosting provider records your IP address, the time of the request and user-agent information about your browser and device in Cloudflare Pages’ standard access logs.

For details, see the privacy policy in Korean.

Calculations run in your browser using the KST calendar date. The saved list is kept only in this browser, with no server sync or backup. Opening a link that carries a date sends that date to the hosting server as part of the request URL. If you choose to include the event name in a shared link, the name is sent too and anyone with the link can see it. See “Privacy on this page” for information about access data.