Recording Lunar Dates: Why You Need a System to Convert Them for You

The Shifting of Lunar Dates: Different Every Year

The Gregorian calendar we use daily is based on the solar cycle, with a year lasting approximately 365 days. The lunar calendar (農曆 nónglì) balances both the moon's phases and seasonal changes, with a common year lasting only about 354 days.

The difference in length between these two calendar systems accumulates to roughly 11 days each year. Consequently, the same lunar date, such as "the fifteenth day of the seventh month," falls on a different position in the Gregorian calendar each year. This year it might be in mid-August; next year it could shift to early August.

This is not a "flaw" of the lunar calendar but an inevitable phenomenon when it operates in parallel with the Gregorian calendar.

Recording the Gregorian Date Yourself Means Recalculating Every Year

Many people record the "Gregorian date" for a lunar birthday or anniversary of death. This works for the current year, but by the next year, that date will be incorrect.

If what matters to you is the lunar date—such as "observing rites on the fifteenth day of the seventh lunar month every year"—then manual conversion must be done annually. Missing one year means a year of regret.

Storing the date as a lunar date and having the system automatically convert it to the corresponding Gregorian date each year is the reason this function exists.

The Special Case of Intercalary Months

To reconcile the discrepancy between solar and lunar cycles, the lunar calendar inserts an intercalary month (閏月 rùnyuè) approximately every two to three years.

If the date you recorded falls in an intercalary month—for example, "the fifteenth day of the intercalary sixth month"—then in years without an intercalary sixth month, that date simply does not exist. The system will not generate a reminder for those years because that date does not occur.

This is something users need to be aware of when setting dates: selecting a date in an intercalary month means you only need a reminder in "years when that month appears."

Reminders Are Only Sent via On-Site Messages, Not Email

The date reminders you set will only appear as on-site messages within your account; they will not be sent to your email inbox.

This is a deliberate design choice. One reason relates to privacy: titles like "Anniversary of Mother's Passing" are not suitable for appearing in the notification bar, lock screen, or email preview on a shared computer. An email from this site with that subject line is exactly what we aim to avoid.

Your Dates Are Visible Only to You

The lunar dates you record are only visible to you after you log into your account. They are not displayed to other users and are not used for any form of analysis or statistics.

This is clearly stated in this site's privacy policy: Article 2 explains the scope of collection and use of personal data, and Article 5 explains users' right to request the deletion of personal data. The dates you record are part of your personal data.

If you choose to delete your account, these dates will be deleted along with it. If an account remains inactive for one year, the system will automatically clear these date records, while the account itself is preserved.

What This Function Does

The lunar date function provided by this site allows you to record specific dates using the lunar calendar. The system automatically converts them to the corresponding Gregorian dates each year and reminds you via on-site messages before the date.

That is all it does: conversion, reminders, and privacy protection. Nothing more, and nothing more is needed.