Possible Clues:

• Combining the first letters of five consecutive ones spells JASON
• May as well as others
• Parts of a year
• 12 in a year
• Some like June and Maureen having short time in health organisation
• Parts of the year (days?) involve taking holidays, primarily
• Year's divisions
• Threesome in a quarter
• Those in 5 and 24 down on both sides of march
• Quarter's threesome