Did Nokia make a mistake? In April of the lunar calendar, other people's mobile phones are 30 days. Why is mine 29 years old? Please explain.

There are only 29 days in April this year. The following is whether there is a 30-day rule in April every year. "None" means that there is no 30th. If there is, it will follow the date of the new calendar ~ Could it be that the landlord is the birthday of the new calendar on April 30th, and so am I ~ So I was shocked after reading the following rules ... I hope it will be useful to the landlord ~

20 13 April 30th-None

20 14 April 30th to May 28th of the lunar calendar

20 15 April 30th of the lunar calendar-None

20 16 April 30th-None

20 17 April 30th to May 25th in the lunar calendar.

20 18 April 30th to June of the lunar calendar 13

20 19 April 30th of the lunar calendar-None

Lunar April 30th-None

20 2 1 April 30th of the lunar calendar-None

20 April 30, 20 22 Lunar New Year-None

April 30th-June17th, October 23rd of the lunar calendar.

20 April 30, 20 24 Lunar New Year-None

20: 25 on April 30, Lunar New Year-None

20 April 30, 20 26 Lunar New Year-None

April 30th to June 4th in the lunar calendar.

April 30, 20 28 Lunar New Year-adoption is hopeless ~