Time-zone and date arithmetic server. Looks trivial but solves a recurring agent failure mode: getting 'today' wrong across zones.
From Wikipedia
Time is the continuous progression of existence that occurs in an apparently irreversible succession from the past, through the present, and into the future. Time dictates all forms of action, age, and causality, being a component quantity of various measurements used to sequence events, to compare the duration of events, and to quantify rates of change of quantities in material reality or in the conscious experience. Time is often referred to as the fourth dimension and the temporal dimension, in addition to the three spatial dimensions.