quarter-hourly

quarter-hourly (not comparable)

1. Occurring every fifteen minutes.
   • 1827, Edward Boys, “Narrative of a Captivity and Adventures in France and Flanders, between the Years 1803 and 1809”, in William Jerdan, William Ring Workman, John Morley, editors, The Literary Gazette‎:

     With the utmost precaution we crept upon the summit, and down the breast-work towards the onter edge of the rampart, when the sentinel made his quarter-hourly cry of “Sentinelle, prenez garde à vous,” similar to our “All's well"

   • 2011, Bhuvan Unhelkar, Green IT Strategies and Applications: Using Environmental Intelligence‎:

     For example, currently, smart meters can be configured to generate hourly, half-hourly, or quarter-hourly readings

quarter-hourly (not comparable)

1. Every fifteen minutes.
   • 1906, Boyd's Blue Book: A Directory from Selected Streets of Philadelphia and Surroundings‎:

     We can furnish Bells, Tubes or Tongs, which can be attached to any Clock, arranged to strike quarter hourly the Westminster or Whittington Chimes

   • 1910, Harper's Magazine‎, volume 120, page 73:

     Only upon this quiet there broke quarter-hourly the chimes of the Church of the Sorbonne, completing, at the hour, a bar of music.

   • 1915, Factory, the Magazine of Management‎, volume 14, page 233:

     These projecting spikes passed an opening in the dial quarter hourly and at such times could be pushed in. If any spikes were left protruding in the morning the watchman had to give a satisfactory explanation.