You might have better luck with picking a saint whose feast day is in August. A lot of church saints are so old that the exact day/date of their birth is uncertain. The following feast days are in August:
Aug 1--St. Alphonsus Liguori, bishop & doctor
Aug 2--St. Ptere Julian, Eymard, priest
Aug 4--St. John Mary Vianney "Cure' of Ars"
Aug 7--St. Sixtus II pope & martyr
Aug 8 St. Dominic--priest propagated devotion to the Rosary
Aug 10-- St. Lawrence deacon & martyr
Aug 11-- St. Clare, virgin
Aug 13-- St. Pontian, pope & martyr, St. Hippolytus, Priest & martyr
Aug 14-- St. Maximillian Mary Kolbe Priest & Martyr he died in Auschwitz Nazi death camp
Aug 15-- Assumption of Blessed Virgin Mary
Aug. 16-- St. Stephen of Hungary
Aug 18-- St. Jane Frances de Chantal, religious
Aug 19-- St. John Eudes priest
Aug 20-- St. Bernard, abbot & doctor
Aug 21 -- St. Pius X, pope
Aug 22-- The Queenship of Mary
Aug 23-- St. Rose of Lima, virgin
Aug 24-- St. Bartholomew, apostle
Aug 25-- St. Louis of France (King Louis IX)
Aug. 27-- St. Monica, mother of st. Augustine
Aug 28-- St. Augustine, bishop and doctor
Aug 29-- The Martyrdom of St. John the Baptist