Is there a day just for twins? Of course. Each December 18th, there’s a day for twins and multiples. The tradition started in 1819 when identical twins in Millsville, OH donated land and renamed the city Twinburg.
Novels about twins you ought to read:
Hepworth, Sally. The Good Sister.
Lea, Caroline. The Metal Heart.
McGuire, Seanan. Down Among the Sticks and Bones.
Morgan, Ann. Beside Myself. (Overdrive eBook).
Nelson, Jandy. I’ll Give You The Sun.
Niffenegger, Audrey. Her Fearful Symmetry.
Rowell, Rainbow. Fangirl.
Roy, Arundhati. God of Small Things.
Score, Lucy. Things We Never Got Over.
Setterfield, Diane. The Thirteenth Tale.
Shamsie, Kamila. Home Fires. A British Muslim twin tries to save her brother from the lure of terrorism.
Smith, Zadie. White Teeth.
Verghese, Abraham. Cutting For Stone.