structural:expansion
Precise clocks

Generally, the regularity of pulsar emission does not rival the stability of atomic clocks. They can still be used as external reference. For example, J0437−4715 has a period of 0.005 757 451 936 712 637 s with an error of 1.7 × 10 s.This stability allows millisecond pulsars to be used in establishing ephemeris time or in building pulsar clocks.

Timing noise is the name for rotational irregularities observed in all pulsars. This timing noise is observable as random wandering in the pulse frequency or phase. It is unknown whether timing noise is related to pulsar glitches. According to a study published in 2023, the timing noise observed in pulsars is believed to be caused by background gravitational waves. Alternatively, it may be caused by stochastic fluctuations in both the internal (related to the presence of superfluids or turbulence) and external (due to magnetospheric activity) torques in a pulsar.