Time scale may refer to:

• Time standard, a specification of either the rate at which time passes, points in time, or both
• A duration or quantity of time:
  • Orders of magnitude (time) as a power of 10 in seconds;
  • A specific unit of time
• Geological time scale, a scale that divides up the history of Earth into scientifically meaningful periods

In astronomy and physics:

• Dynamical time scale, in stellar physics, the time in which changes in one part of a body can be communicated to the rest of that body, or in celestial mechanics, a realization of a time-like argument based on a dynamical theory
• Nuclear timescale, an estimate of the lifetime of a star based solely on its rate of fuel consumption
• Thermal time scale, an estimate of the lifetime of a star once the fuel reserves at its center are used up

In cosmology and particle physics:

• Planck time, the time scale beneath which quantum effects are comparable in significance to gravitational effects

In mathematics:

• Time-scale calculus, the unification of the theory of difference equations with differential equations

In music:

• Rhythm, a temporal pattern of events
• Time scale (music), which divides music into sections of time

In project management:

• Man-hour, the time scale used in project management to account for human labor planned or utilized