Tell me what time it is.

Time is one of the seven basic physical quantities in physics, with the symbol T. In the International System of Units (SI), the basic unit of time is seconds, with the symbol S. The definition of seconds in the 13 International Conference on Weights and Measures held in 1967 is: 9 of the radiation corresponding to two hyperfine energy level transitions in the ground state of cesium-133. The cesium atom mentioned in this definition must be at rest at absolute zero, and the environment on the ground is zero magnetic field. The second defined in this case is equivalent to the second defined in the astronomical almanac. The time units commonly used in life are: millisecond ms, minute min, hour h and day d.

Definition of time: the connotation is endless, and the extension is a measure of the length and occurrence order of all events.

"Endless" means that time has no beginning or end, and "forever" means that the increment of time is always positive.

Time expresses the birth and death arrangement of objects. "Time" is short for "Time".