D-Day Keep Terms of Service

First Published: May 21, 2026 · This Revision Published: August 20, 2026

Notice of Upcoming Amendment — Effective September 24, 2026
Amended Terms replacing those below take effect on September 24, 2026. Because they include changes disadvantageous to users, they are posted 30 days in advance. Key changes: redesigned amendment procedure (non-disadvantageous changes take effect upon posting), a new article on service limitations and user responsibility, adjusted disclaimers, a new liability cap for paid products, and new user obligations. The full text is available at the bottom of this page. Questions: support@codesand.co.kr

These Terms govern the relationship between CodeSand Co., Ltd. ("Company") and users of the mobile application "D-Day Keep" ("Service"), setting out the rights, obligations, and responsibilities of both parties.

1. Definitions

2. Effect and Changes to the Terms

These Terms take effect when posted on the Service website, and Users may review them at any time via the in-app settings menu.

The Company may amend these Terms within the bounds of applicable law. When amending, the Company will post the amended contents and their effective date on the Service website at least 7 days before the effective date, or at least 30 days before the effective date for changes disadvantageous to Users.

If a User continues to use the Service after the effective date of the amended Terms, the User is deemed to have agreed to them. A User who does not agree to the amended Terms may stop using the Service, and Members may delete their account at any time.

3. Use of the Service

4. Provision of the Service

The Company provides a D-Day service for registering dates you want to remember and managing them as countdowns. Key features include, by way of example:

Specific feature layouts and usage are described in the app. The Company may modify, add, or discontinue individual features to improve service quality and stability. Changes that materially affect Users, such as discontinuation of the entire Service, will be announced in advance by the method set out in Article 2.

5. User Obligations and Prohibited Acts

Users must not engage in the following:

6. Rights and Responsibilities for Content

7. Advertising

The Company may display in-app advertisements (such as AdMob) to operate the Service. Ad frequency and placement are adjusted within a range that does not harm user experience. Ads are not shown to Users who have purchased the ad-removal product (see Article 8).

8. Paid Products, Payment, and Refunds

The Company sells the following paid products within the app. All existing free features remain available regardless of whether a User purchases any paid product.

Payment is processed through the in-app purchase system of the app marketplace the User uses (Apple App Store or Google Play). Prices, payment methods, and currency follow the policies of each marketplace. The Company does not directly collect or store payment-instrument information such as credit card numbers.

Refunds (including statutory withdrawal of purchase) are handled according to the refund policies and procedures of the marketplace that processed the payment:

Users may withdraw a purchase as provided by applicable law, including the Korean Act on Consumer Protection in Electronic Commerce. However, under Article 17(2) of that Act, withdrawal may be restricted for digital content whose provision is completed immediately upon purchase (such as ad removal) once provision has begun; the Company indicates this on the purchase screen before payment. Nothing in this Article limits rights guaranteed to Users under applicable law.

9. Service Restrictions

If a User violates these Terms or applicable law, the Company may take the following measures, in stages or immediately:

In cases of serious violation, measures may be taken without prior notice, and the User may file an objection with the Company.

10. Account Deletion and Loss of Membership

Members may request account deletion at any time via the in-app "Settings → Delete Account" menu. Upon deletion, the Member's identification data (account, email, social-linked tokens), all registered D-Days, and all uploaded photos are permanently deleted immediately or within a designated period. This cannot be reversed.

However, information may be retained for a limited period in the following cases:

For details on retained items and periods, please refer to the Privacy Policy.

11. Personal Information Protection

The Company strives to protect Users' personal information. Matters concerning the collection, use, and provision of personal information are governed by the separate Privacy Policy.

12. Disclaimer

13. Dispute Resolution and Jurisdiction

If a dispute arises between the Company and a User in connection with these Terms, both parties shall resolve it in good faith through consultation. Any litigation that cannot be resolved through consultation shall be filed with the court of competent jurisdiction under the Korean Civil Procedure Act. These Terms shall be interpreted under, and disputes between the Company and Users shall be governed by, the laws of the Republic of Korea.

14. Contact

Supplementary Provisions

Effective Date: August 27, 2026 (originally effective May 21, 2026)


© 2026 CodeSand Co., Ltd.


Amended Terms Effective September 24, 2026 (Full Text)

The following is the full text of the amended Terms that will replace the Terms above on September 24, 2026. Published August 25, 2026. Until the effective date, the Terms above apply.

1. Purpose and Definitions

The purpose of these Terms is to set out the conditions and procedures for using the mobile application "D-Day Keep" (the "Service") provided by CodeSand Co., Ltd. (the "Company"), together with the rights, obligations, and responsibilities of the Company and its Users.

The terms used in these Terms have the following meanings.

2. Effect and Amendment of the Terms

These Terms take effect upon being posted on the Service website, and Users may review them at any time from the in-app settings menu.

The Company may amend these Terms within the bounds of applicable law.

An amendment that is not disadvantageous to Users is posted on the Service website stating the amended content and the effective date, and takes effect at the same time as it is posted. The addition of features, editorial cleanup, clarification of the items collected and used, and correction of typographical errors fall into this category.

An amendment that is disadvantageous to Users is posted on the Service website stating the amended content and the effective date, from 30 days before the effective date. Changes that reduce Users' rights or impose new obligations, discontinuation of a feature previously provided, and narrowing of refund conditions fall into this category.

If a User continues to use the Service after the effective date of the amended Terms, the User is deemed to have agreed to them. A User who does not agree may stop using the Service at any time; termination of the use agreement is governed by Article 11.

3. Provision of the Service

The Company provides the features necessary to achieve the purpose of the Service. The specific composition and use of each feature are explained on the app screens, and the list below is an illustration of the nature of the Service and does not limit the features the Company provides.

D-Day sharing takes place only when a User requests it, and is available regardless of whether the User is a Member. When a share link is created, the information of that D-Day is stored on the Company's servers exactly as it stands at the time of sharing, and anyone who knows the link can view it without signing in. A share link expires 90 days after the date it was created, and if the User deletes the D-Day, the share link is withdrawn along with it.

The Company may modify, add, or discontinue individual features in order to improve the quality of the Service and operate it reliably. However, a change that materially affects Users, such as discontinuation of the entire Service, will be posted in advance by the method set out in Article 2.

The Service is provided year-round as a matter of principle, but it may be temporarily suspended where there is substantial cause, such as system maintenance, replacement of equipment, or an outage of an external service. In such a case the Company will give advance notice to the extent possible and will resume without delay once the cause is resolved.

If the Company terminates the provision of the Service as a whole, it will give notice by posting on the Service website at least 30 days in advance. Users may review the D-Days and photos they have registered before termination and keep whatever they need separately.

4. Limits of the Service and User Responsibility

This Article sets out what you must check before using the Service. The Service has the limits described below, and Users use the Service with an understanding of them. Article 13 (Disclaimer) is premised on this Article.

a. D-Day calculation

The number of days remaining is calculated on the basis of the date and time set on the User's device. If the device's date, time, or time-zone settings differ from the actual ones, the number of days displayed may differ as well.

b. Delivery of notifications

Notifications are scheduled and sent on the device. Depending on whether notification permission has been granted, the operating system's power-saving and battery-optimization policies, the power state of the device, force-quitting of the app, and similar factors, a notification may be delayed or may not be sent at all. The Company does not warrant that notifications will always arrive at the exact time, and Users must not rely on the Service's notifications alone for important schedules.

c. Retention of data

D-Days registered by a Guest are stored only inside the device, so they cannot be recovered if the app is deleted or the device is lost. The cloud backup provided to Members is a supplementary means and does not guarantee complete preservation. Users are themselves responsible for separately managing important data.

d. Share links

A share link can be viewed by anyone who knows it, so Users must decide for themselves to whom they send a link. The Company cannot control the onward forwarding of a link that has already been sent to a third party.

e. Reliance on external services

Sign-in, data storage, notifications, advertising, and payment are provided using the services of external providers, so some features may be limited by those providers' policy changes or outages.

5. Modes of Use and Accounts

6. User Obligations and Prohibited Acts

Users must not engage in any of the following acts.

  1. Misappropriating another person's information or registering false information
  2. Registering or uploading obscene material, violent content, or discriminatory or hateful expression
  3. Registering or uploading content that infringes the rights of others, such as copyrights, trademarks, or portrait rights
  4. Interfering with the normal operation of the Service, such as by using automated tools or generating abnormal traffic
  5. Reverse-engineering the Service, or reproducing, distributing, or commercially exploiting any part of the Service without the Company's permission
  6. Circumventing the payment system or acquiring entitlements to Paid Products by improper means
  7. Any other act contrary to applicable law or these Terms

7. Rights and Responsibilities for Content

8. Advertising

The Company displays advertisements within the app in order to operate the Service and provide it free of charge. The placement and frequency of advertisements are set within a range that does not interfere with Users' use of the Service, and the Company may change the form and manner in which advertisements are displayed.

Advertisements are not displayed to Users who have purchased the ad-removal product under Article 9.

Advertisements are served through external advertising providers, so their content is not written by the Company. Transactions concerning the goods or services shown in an advertisement take place between the User and the advertiser concerned, and the Company is not involved in those transactions. Matters concerning the identifiers used to serve advertisements are set out in the Privacy Policy.

9. Paid Products, Payment, and Refunds

The Company provides the following Paid Products within the app. Features provided free of charge remain available regardless of whether a Paid Product is purchased, and signing up as a Member is not required in order to purchase a Paid Product.

Remove AdsNon-consumable product
Description
A one-time purchase after which advertisements are no longer displayed in the app.
Entitlement
Tied to the App Marketplace account used to pay. It is not tied to a Member account with the Company.
Restoration
If you change devices or reinstall the app, running "Restore purchases" in the app with the same App Marketplace account restores the entitlement.
SupportConsumable product
Description
A voluntary donation to cheer on the operation of the Service.
Consideration
No separate feature, goods, or benefit is provided in return for a donation.
Frequency
It is consumed each time it is purchased and may be purchased any number of times. It is not subject to restoration.

The Company may change the type, price, or composition of Paid Products or discontinue their sale. However, rights already acquired by Users who have completed payment are not retroactively reduced or otherwise affected by such a change.

Payment

The seller of Paid Products is the operator of each App Marketplace (Apple Inc. or Google LLC), and payment is processed through the in-app purchase system of that App Marketplace. Prices, currency, payment methods, and the handling of taxes follow the policies of each App Marketplace and the settings of the App Marketplace account the User uses.

The Company does not collect or store payment-instrument information such as credit card numbers, and is not involved in the payment process. Payment errors, duplicate payments, and payment cancellations are handled through the procedures of each App Marketplace.

Where a minor has made a payment without the consent of their legal representative, the minor or the legal representative may cancel that payment under the Civil Act of Korea. Even in that case, the cancellation procedure is carried out through the App Marketplace that processed the payment.

Refunds and Withdrawal of Purchase

Under Article 17 of the Act on the Consumer Protection in Electronic Commerce, etc. of Korea, a User may in principle withdraw a purchase within 7 days from the date of purchase. However, under paragraph 2 of the same Article, withdrawal of purchase may be restricted for digital content whose provision is completed immediately upon purchase, once its provision has begun. Because the party that processed the payment is the App Marketplace, refunds (including withdrawal of purchase) likewise follow the refund policy and procedures of each App Marketplace.

The Company presents the nature of each product and the fact that withdrawal may be limited on the payment screen before purchase.

Where a product differs from what was indicated or advertised, or is defective, the User may withdraw the purchase in accordance with applicable law. Rights guaranteed to Users by applicable law are not limited by this Article.

10. Restrictions on Use of the Service

If a User violates these Terms or applicable law, the Company may take the following measures, in stages or immediately.

  1. Making the User Content concerned private, or deleting it
  2. Withdrawal of the share link
  3. Restriction of Service use for a specified period
  4. Permanent suspension of the Member account, or termination of the use agreement

Before taking a measure, the Company will inform the User of the grounds and the period and give the User an opportunity to explain. However, where there is an urgent cause — such as a serious infringement of another person's rights or serious interference with the operation of the Service — the Company may act first and inform the User afterwards.

A User may object to a measure through the contact point in Article 15, and where the objection is well founded the Company will lift the measure without delay.

Because entitlements to Paid Products are tied to the App Marketplace account, a restriction on use under this Article does not in itself constitute grounds for a refund of a Paid Product already purchased.

11. Termination of the Use Agreement

A Member may withdraw at any time from Settings → Account → Delete Account in the app. Once the withdrawal procedure is complete, all D-Days the Member registered and all photos they uploaded are deleted, and deleted data cannot be recovered.

A Guest may end their use of the Service by deleting the app. In that case the data stored inside the device is deleted along with the app.

The Company may terminate the use agreement where a User has committed a serious violation falling under Article 10, and will inform the User of the grounds for and the time of the termination.

Even after withdrawal or termination, information may be retained for a certain period where there is a retention obligation under applicable law or where the information is necessary to prevent fraudulent use. The specific scope and periods of the items deleted and the items retained are set out in the Privacy Policy.

Even after withdrawal, entitlements to Paid Products purchased remain with the App Marketplace account, so if you reinstall the app with the same App Marketplace account you can recover them with "Restore purchases".

12. Personal Information Protection

The Company protects Users' personal information in accordance with applicable law, including the Personal Information Protection Act of Korea. Matters concerning the collection, use, provision, outsourcing, overseas transfer, retention period, and destruction of personal information are set out in a separate Privacy Policy.

13. Disclaimer

The limitations of liability in this Article do not apply to damage caused by the Company's intent or gross negligence, and do not limit rights guaranteed to Users by applicable law.

14. Dispute Resolution and Jurisdiction

The laws of the Republic of Korea apply to the interpretation of these Terms and to disputes between the Company and Users.

If a dispute arises in connection with use of the Service, the Company and the User shall resolve it through consultation in accordance with the principle of good faith; litigation concerning a dispute that cannot be resolved through consultation shall be filed with the court of competent jurisdiction under the Civil Procedure Act of Korea.

Before litigation, a User may apply for mediation of the dispute to a relevant body such as the Consumer Counseling Center of the Korea Consumer Agency or the Personal Information Dispute Mediation Committee.

However, where a User is a consumer residing in a country other than the Republic of Korea, rights guaranteed by the mandatory provisions of that country are not limited.

15. Contact

Supplementary Provisions

Effective Date: September 24, 2026 (originally effective May 21, 2026)


© 2026 CodeSand Co., Ltd. Business Registration No. 368-87-03020.