DAYDEGREE
day-degree: translation
a unit taking temperature and time in days into consideration to indicate degree of development. Calculated by adding the average daily temperature for each day, e.g. if the average daily temperatures that a 3-day-old trout egg has been subjected to are 11, 12 and 13 degrees centigrade, the eggs are at the 36 day degree stage. This is abbreviated 36 D. Abbreviation Dº