TimeTaiSeconds

class sunpy.time.TimeTaiSeconds(val1, val2, scale, precision, in_subfmt, out_subfmt, from_jd=False)

Bases: TimeFromEpoch

SI seconds from 1958-01-01 00:00:00, which includes UTC leap seconds.

1958-01-01 00:00:00 is the defined time when International Atomic Time (TAI) and Universal Time (UT) are synchronized. A TAI second has the same length as an SI second, but prior to 1972-01-01, a UT second – then defined to be 1/86400 of an Earth day – grew to be longer than than an SI second. 1972-01-01 00:00:00 UTC is equal to 1972-01-01 00:00:10 TAI. After 1972-01-01, Coordinated Universal Time (UTC) is defined with seconds that are the same length as SI seconds, but now leap seconds are occasionally added to UTC so that it stays synchronized with Earth days.

Notes

This format is equivalent to the output of the SSW anytim2tai routine, and related routines, for times after 1972-01-01. Be aware that the SSW routines are not written to provide valid results for times before 1972-01-01.

This format is equivalent to TimeUnixTai, except that the epoch is 12 years earlier.

References

• anytim2tai routine in SSW

Examples

>>> from astropy.time import Time
>>> t = Time('1958-01-01T00:00:00', format='isot', scale='tai')
>>> t.tai_seconds
0.0
>>> t2 = Time('2015-10-25T05:24:08', format='isot', scale='tai')
>>> t2.tai_seconds
1824441848.0
>>> t3 = Time(t2.tai_seconds, format='tai_seconds')  # scale is automatically TAI
>>> t3.isot
'2015-10-25T05:24:08.000'

Attributes Summary

epoch_format
epoch_scale
epoch_val
epoch_val2
name
unit

Attributes Documentation

epoch_format = 'iso'

epoch_scale = 'tai'

epoch_val = '1958-01-01 00:00:00'

epoch_val2 = None

name = 'tai_seconds'

unit = 1.1574074074074073e-05