1. The First Day of Summer: June 21 marks the official first day of summer in Texas and across the Northern Hemisphere. The solstice, which occurs when the Earth's tilt is the most inclined towards the Sun, is celebrated by many cultures and is considered a time of renewal, growth, and joy.

2. National Selfie Day: June 21 is also National Selfie Day in the United States. This unofficial holiday encourages people to take and share photos of themselves with their friends and followers on social media. Selfie enthusiasts can find plenty of great spots around Texas to snap a picture, from the Alamo in San Antonio to the beach in Galveston.

3. Father's Day: In many years, June 21 is also Father's Day in the United States. This special day honors the important role that fathers and father figures play in our lives. Texans can celebrate their dads with a barbecue, a day on the golf course, or by spending time together exploring the state's natural beauty.

4. Juneteenth: Juneteenth, also known as Emancipation Day, is a historically significant holiday celebrated on June 19 in Texas and many other states. The holiday commemorates the day in 1865 when Union General Gordon Granger arrived in Galveston and announced that slavery had been abolished in Texas. Many Texans mark the occasion with parades, festivals, and other community gatherings.

5. Texas Flag Day: June 21 is also recognized as Texas Flag Day in honor of the adoption of the Lone Star Flag as the official state flag in 1839. The flag's distinctive design, which features a single white star on a field of blue flanked by two horizontal bars of white and red, is instantly recognizable and has become a symbol of Texas pride and identity. Texans can show their love for the Lone Star State by flying the flag at home, wearing Texas-themed clothing, or visiting a local historic site such as the Texas State Capitol.