ΔT

The symbols Δt and ΔT (spoken as "delta T") are commonly used in a variety of contexts.

Time

 * ΔT (timekeeping) the difference between two time scales, Universal Time and Terrestrial Time, which results from a drift in the length of a day
 * The interval of time used in determining velocity
 * The increment between successive nerve impulses

Temperature

 * To mean a difference in temperature including thermodynamic temperature, may occur in
 * Discussions of climate change
 * Discussions of heat transfer
 * Discussions of the effects of thermal gradients