Most months of the year have about three major feast days; June is right on the average with that number: Saint Barnabas on the 11th, The Nativity of Saint John the Baptist on the 24th, and Saints Peter and Paul on the 29th.
Being in the first half of the month, Saint Barnabas’ Day often lands close to Trinity Sunday or Pentecost. While this can sometimes cause a little trouble with displacing the Ember Days or transferring Barnabas away from those highest of Sundays, it also makes a lot of sense to celebrate him in proximity to the Day of Pentecost. The reason is simple: the book of Acts is associated with the season of Eastertide as well as the Day of Pentecost, so there’s a biblical-chronological sense to getting to the story of Barnabas on the heels of Pentecost.
The Nativity (birth) of St. John the Baptist, meanwhile, is in June for historical reasons; it’s linked with the dates for the Annunciation to Mary and the birth of Christ. You can read more about that here!
Saints Peter and Paul were both martyred in Rome. It happened at different times, possibly in different years, although both within a few years of one another in the mid-to-late-60’s. Their martyrdoms have traditionally been observed together on the same date, June 29th.
Among the Optional Commemorations there are a few that the Saint Aelfric Customary would highlight as Minor Feasts:
- 1 June: St. Justin Martyr, one of the first major apologists
- 14 June: St. Basil the Great, one of the Cappadocian Fathers, great theologians
- 22 June: St. Alban, the first martyr in Britain
- 27 June: St. Cyril of Alexandria, a key leader at the Council of Ephesus
- 28 June: St. Irenaeus, a major 2nd century Christian writer