1. Lunar Date: If your invitation is written according to the lunar date, you can write the lunar date on the invitation in the format of "X year X month X day". For example, if you want to invite guests to celebrate the first day of the first lunar month, you can write "1898 first lunar month" on the invitation.

2. Gregorian calendar date: If your invitation is written according to the Gregorian calendar date, you can write the Gregorian calendar date on the invitation in the format of "X year X month X day". For example, if you want to invite guests to the celebration on April 20th of Gregorian calendar, you can write "2065438+April 20th, 2009" on the invitation.

3. In China culture, branches and the zodiac are also a way to indicate dates. You can write down the branches and zodiac signs of the day on the invitation, such as "Wu Jianian's branches on X month X day: Gengzi Zodiac: Rat".

No matter which writing method you choose, you should pay attention to the arrangement of the date, ensure that the numbers and words of the date are clear and easy to read, and let the guests understand the date you invited accurately.