Question: Patrick Warren and David Spencer vanished on the holiday that is celebrated on the day after what other holiday?

Context articles: Saint Patrick's Day in the United States
Public holidays in Singapore
Public holidays in the United States
Saint-Jean-Baptiste Day
Boxing Day
Public holidays in Japan
Disappearance of Patrick Warren and David Spencer
Thanksgiving (United States)
Prešeren Day
Garifuna Settlement Day

Saint Patrick's Day, although a legal holiday only in Suffolk County, Massachusetts (where it is recognized alongside Evacuation Day) and Savannah, Georgia, is nonetheless widely recognized and celebrated throughout the United States.
 It is primarily celebrated as a recognition of Irish and Irish American culture; celebrations include prominent displays of the color green, eating and drinking, religious observances, and numerous parades.
 The holiday has been celebrated on the North American continent since the late 18th century.
There are eleven public holidays in Singapore.
 Each major local race and religion have two holidays each in addition to the secular holidays of New Year's Day, Labour Day and National Day.
 For the Chinese, Chinese New Year (two days) and the Buddhist holiday Vesak Day (one day) are also observed.
 For the Hindus, the Hindu holiday of Vesak Day and Deepavali (one day each) are celebrated.
 For the Malays, the two Islamic holidays of Hari Raya Aidil Fitri (one day on 1 Syawal) and Hari Raya Aidil Adha (one day on 10 Zulhijah) are celebrated.
 As for the Christians, the two Christian holidays of Good Friday and Christmas Day (25 December) are celebrated.
 These public holidays have been recognised since Singapore's 1968 Employment Act.
Public holidays in the United States are largely controlled by private sector employers, who employ approximately 62% of the total U.S. population who are given paid time off.
 A typical work week is generally 40 hours a week with a Saturday-Sunday weekend.
 Public holidays with paid time off is generally defined to occur on a day that is within the employee's work week.
 When a holiday occurs on Saturday or Sunday, that holiday is shifted to either Friday or Monday.
 Most employers follow a holiday schedule similar to the federal holidays of the United States, with exceptions or additions.
 The federal holiday schedule mainly benefits employees of government and government regulated businesses.
 However, this sector only comprises 15% of the working population.
 At the discretion of the employer, other non-federal holidays such as Christmas Eve and the Day after Thanksgiving are common additions to the list of paid holidays while Columbus Day and Veterans Day are common omissions.
 Besides paid holidays are festival and food holidays that also have wide acceptance based on sales of goods and services that are typically associated with that holiday.
 Halloween and Valentine's Day are such examples of widely celebrated uncompensated holidays.
Saint-Jean-Baptiste Day (French: "Fête de la Saint-Jean-Baptiste" ), officially known in Quebec as the National Holiday, (French: "la fête nationale" ) is a holiday celebrated annually on June 24, the feast day of the Nativity of St. John the Baptist.
 In Quebec, it is a public holiday with festivities occurring on June 23 and 24 which are publicly financed and organized by a "Comité organisateur de la fête nationale" (National Holiday Organizing Committee).
 June 24 is also celebrated as a festival of French Canadian culture in other Canadian provinces and the United States.
Boxing Day is a holiday celebrated the day after Christmas Day.
 It originated in the United Kingdom, and is celebrated in a number of countries that previously formed part of the British Empire.
 Boxing Day is on 26 December, although the attached bank holiday or public holiday may take place either on that day or two days later.
Public holidays in Japan (国民の祝日 , kokumin no shukujitsu ) were established by the Public Holiday Law (国民の祝日に関する法律 , Kokumin no Shukujitsu ni Kansuru Hōritsu ) of 1948 (as amended).
 A provision of the law establishes that when a national holiday falls on a Sunday, the next working day shall become a public holiday, known as furikae kyūjitsu (振替休日 , literally "transfer holiday") .
 Additionally, any day that falls between two other national holidays shall also become a holiday, known as kokumin no kyūjitsu (国民の休日 , literally "citizens' holiday") .
 May 4, sandwiched between Constitution Memorial Day on May 3 and Children's Day on May 5, was an annual example of such a holiday until it was replaced by Greenery Day in 2007.
Patrick Warren and David Spencer were two English schoolboys who mysteriously vanished on 26 December Boxing Day 1996 in the town of Solihull, near Birmingham, and to this day no traces of them have ever been found.
 Despite numerous appeals from both families, including a Crimewatch special report, the case remains open and is one of the more notorious cases of missing children in U.K. history.
Thanksgiving, or Thanksgiving Day, is a public holiday celebrated on the fourth Thursday of November in the United States.
 It originated as a harvest festival.
 Thanksgiving has been celebrated nationally on and off since 1789, after Congress requested a proclamation by George Washington.
 It has been celebrated as a federal holiday every year since 1864, when, during the American Civil War, President Abraham Lincoln proclaimed a national day of "Thanksgiving and Praise to our beneficent Father who dwelleth in the Heavens," to be celebrated on the last Thursday in November.
 Together with Christmas and the New Year, Thanksgiving is a part of the broader holiday season.
The Prešeren Day, the full name being Prešeren Day, the Slovene Cultural Holiday (Slovene: "Prešernov dan, slovenski kulturni praznik" ), is a public holiday celebrated in Slovenia on 8 February.
 It is marking the anniversary of the death of the Slovene national poet France Prešeren on 8 February 1849 and is the celebration of the Slovenian culture.
 It was established in 1945 to raise the cultural consciousness and the self-confidence of the Slovene nation, and declared a work-free day in 1991.
 On February 7, the eve of the holiday, the Prešeren Awards and the Prešeren Fund Awards, the highest Slovenian recognitions for cultural achievements, are conferred.
 Prešeren Day continues to be one of the most widely celebrated Slovene holidays.
 It is not only celebrated in Slovenia, but by Slovene communities all around the world.
Garifuna Settlement Day is a public holiday in Belize, celebrated each year on November 19.
 The holiday was created by Belizean civil rights activist, Thomas Vincent Ramos, in 1941.
 It was recognized as a public holiday in the southern districts of Belize in 1943, and declared a national holiday in 1977.
 The holiday celebrates the settlement of the Garifuna people in Belize after being exiled from the Grenadines by the British army.
 The major festivities for the holiday occur in the town of Dangriga, including parades, street music, and traditional dancing.