Swift Mission Epoch (gdt.missions.swift.time)

The Swift Mission epoch, also called the Swift Mission Elapsed Time (MET) is the number of seconds elapsed since January 1, 2001, 00:00:00 UTC, including leap seconds. We have defined a specialized epoch to work with Astropy Time objects so that Swift MET can be easily converted to/from other formats and time scales.

To use this, we simply import and create an astropy Time object with a ‘swift’ format:

>>> from gdt.missions.swift.time import Time
>>> swift_met = Time(697422649, format='swift')
>>> swift_met
<Time object: scale='tt' format='swift' value=697422649.0>

Now, say we want to retrieve the GPS timestamp:

>>> swift_met.gps
1359765062.0

The Astropy Time object readily converts it for us. We can also do the reverse conversion:

>>> gps_time = Time(swift_met.gps, format='gps')
>>> gps_time
<Time object: scale='tai' format='gps' value=1359765062.0>

>>> gps_time.swift
697422649.0

And we should, of course, get back the Swift MET we started with. This enables you do do any time conversions already provided by Astropy, as well as time conversions between other missions within the GDT.

In addition to time conversions, all time formatting available in Astropy is also available here. For example, we can format the Swift MET in ISO format:

>>> swift_met.iso
'2023-02-07 00:31:53.184'

Reference/API

gdt.missions.swift.time Module

Classes

SwiftSecTime(val1, val2, scale, precision, ...)	Represents the number of seconds elapsed since Jan 1, 2001, 00:00:00 UTC, including leap seconds
Time(val[, val2, format, scale, precision, ...])	Represent and manipulate times and dates for astronomy.

Class Inheritance Diagram