Holidays are cultural and related to local history and folklore. It's important to be aware that
each culture has different holidays, and even ones with similar themes or names are NOT equivalent, e.g. Qixi and Valentine's Day.
Also, be aware that classic imagery associated with seasons will not apply to different hemispheres: Winter in one hemisphere is summer in the other. The more you tailor for local holidays and climates, the more players will connect with the game.
Below are lists of holidays and seasons divided by country.
Japan has many public holidays, the exact dates of which you can on the official Cabinet website here, with the public holiday dates for the following year announced in February. Here is a rundown:
New Year's Day: Jan. 1
Coming of Age Day (Jan. 8)
Foundation Day (Feb. 11-12)
Emperor's Birthday (Feb. 23)
Vernal Equinox Day (March 20)
Shōwa Day (April 29)
Constitution Day (May 3)
Greenery Day (May 4)
Children's Day (May 5-6)
Marine Day (July 15)
Respect for the Aged Day (Sept. 16)
Autumnal Equinox (Sept. 22-23)
Health and Sports Day (Oct. 14)
Culture Day (Nov. 3-4)
Labor Thanksgiving Day (Nov. 23)
New Year
The new year is typically celebrated from the second half of December to the beginning of January, making it a major vacation period. Most Japanese have time off and Japanese games often have content geared toward this period.
Valentine's Day
While not an official holiday, many in Japan celebrate this on Feb. 14. Customarily, women give chocolates to either: men they are interested in, or to friends/colleagues.
There is also "White Day" on March 14, when people give gifts to those who gave them gifts on Valentine's Day.
New Spring
While not a holiday, April is considered the beginning of a new fiscal year and so is also the beginning of a new school year. Because of this, Japanese society welcomes the new year in April, and many mobile games will have activities/events related to this.
Golden Week
With several public holidays in a row, the first week of May has become a major holiday period in Japan.
Most mobile games in Japan take advantage of the long holiday period to roll out events and other ways to get players engaged.
Note: While China has two "Golden Weeks" (the first week of October and the first week of May), Japan only has one, so language or imagery referring to "Golden Week" will only make sense in Japan for the May holidays.
Summer Holiday/Obon
Japanese schools are always on holiday in August, and around mid-August, Japan also celebrates the Obon festival, which usually lasts 3-5 days. During this time, there are several events, such as fireworks and more, which often appear around this time in mobile games.
Note: While Japan does celebrate the Qixi Festival, there is not a strong sense of tradition around it, and "Chinese Valentine's Day" is not a common term. Qixi Festival falls on July 7 in the lunar calendar, but in Japan it falls on July 7th in the solar calendar. A common tradition at this time is to write notes on bamboo leaves.
Halloween
The holiday may have originated in the West, but Japan has its own Halloween traditions now, which take place at the end of October. In Japan, this often includes young people partaking in costume parades, with pop culture, businesses, and parties reflecting the theme. It is common for Japanese mobile games to launch items/skins related to Halloween.
Christmas Eve + Christmas Day
While not a public holiday, some Japanese people do celebrate Christmas Eve and Christmas Day (Dec. 24-25), and so there are often Christmas-themed products or events in businesses.
Because of its proximity to the New Year, many mobile games in Japan plan more frequent events since it is a major holiday period.
Public Holidays
World Peace Day — January 1st, 1-day holiday
Carnaval — Feb or Mar, moveable date (Lunar Calendar). At least 2.5 days on Mon, Tue, and Wed until 12 pm. Not to be confused with 'carnival' or 'mardi gras', although some elements may look similar.
Holy Friday and Easter — the Friday before Easter Sunday, moveable date (Lunar Calendar), 1-day holiday
Tiradentes — Apr 21st, in honor of a national hero, 1-day holiday
Worker's Day — May 1st, 1-day holiday
Corpus Christi — 60 days after Easter, moveable date (Lunar Calendar), 1-day holiday
Nossa Senhora Aparecida — Oct 12th, national Christian Patron's Day, 1-day holiday
Independence Day — September 7th, 1-day holiday
Finados — Nov 2nd, the day to mourn the dead (akin to Tomb Sweeping), 1-day holiday
Republic Day — Nov 15th, proclamation of the Republic, 1-day holiday
Black Heritage Day (Zumbi) — Nov 20th, to honor African heritage and to Zumbi, an enslaved hero, 1-day holiday
Christmas — Dec 25th, 1-day holiday
Other Important Dates
AUTUMN: from March 21st to June 21st
Indigenous People's Day — April 19th, to honor the original peoples of Brazil
Mother's Day — Second Sunday of May, the second highest-grossing day for retail
Festa Junina — Throughout the months of June and July, parties to celebrate 3 Catholic saints, includes dance and special food
Dia dos Namorados — Jun 12th, the day dedicated to couples and lovers
WINTER: from June 21st to September 23rd
School Winter Break — Usually the whole month of July
Father's Day — Second Sunday of August
SPRING: from September 23rd to December 21st
Children's Day — Oct 12th
School Summer Break —2nd or 3rd week of December, until early February next year
SUMMER: from December 21st to March 21st
Christmas Eve — Dec 24th, optional shorter working day
Réveillon (New Year's Eve) — Dec 31st
Dates THAT ARE NOT Celebrated
Any Chinese holiday (Qixi, Single's Day, Chinese New Year, Dragon Boat, etc.)
Valentine's Day, Saint Patrick's, Thanksgiving, Mardi Gras, Columbus Day, and Halloween
Día de los Muertos, Cinco de Mayo
Public Holidays
New Year's Day — January 1st
Mexican Constitution Day — February 6th
Birthday of Benito Juárez — March 20th (also beginning of Spring)
Holy Week — Apr 3rd to 14th, vacation for students and teachers
Holy Thursday — April 6th, holiday for workers
Holy Friday — April 7th, holiday for workers
International Worker's Day — May 1st
Mexican Independence Day — September 16th
Day of the Dead — Nov 2nd
Mexican Revolution Anniversary — Nov 20th
Christmas — Dec 25th,
Ramadan (March 10-April 9)
Eid ul-Fitr (April 9-10)
Day of Arafah (June 15-16)
Eid al-Adha (Feast of the Sacrifice) (June 16-17)
Milad al-Nabi (Prophet Mohammed’s Birthday) (Evening of Sept. 15-16)
Islamic New Year (July 6-7)
Founding Day (Feb. 22)
Saudi National Day (Sept. 23)
UAE National Day (Dec. 2)
Dubai International Film Festival
Christmas Holiday (Dec. 25 AND Jan. 7, according to the Orthodox calendar)
Sham El Nessim (Easter) (May 6)
Sinai Liberation Day (April 25)
Revolution of 30 June
*NOTE: In addition to paying attention to holidays celebrated in the region, be aware that other holidays may be considered taboo. Valentine's Day, for instance, is considered taboo because public displays of affection between unmarried couples is not permitted in certain countries.
Martin Luther King Jr. Day — January 16
Presidents' Day — February 20
Memorial Day — May 29
Juneteenth — June 19
Independence Day — July 4
Labor Day — September 4
Veterans Day — November 10
Thanksgiving — Fourth Thursday in November
Christmas — December 25
*This list only includes Public Holidays