Synopsis
Defines available calendars and timescales for command line versions of Chandra Proposal Tools
Description
The default timescale types in DATES are: Timescale Timescale Type ----------------------------- TT Terrestrial Time UTC Civil Time TDB Dynamical Time TAI Atomic Time UT1 UT1 Time GMST Sidereal Time LST Local Siderial Time with additional timescales defined as offsets to UTC: Timescale Timescale Name Type Zone Par Zone --------------------------------------------------------------- Local Zone +0000 Civil Time 0 +0000 MST Moscow Summer Time Civil Time 14400 +0400 DMV Moscow Decree Time Civil Time 10800 +0300 BST British Summer Time Civil Time 3600 +0100 GMT Greenwich Mean Time Civil Time 0 +0000 EDT Eastern Daylight Time Civil Time -14400 -0400 EST Eastern Standard Time Civil Time -18000 -0500 CDT Central Daylight Time Civil Time -18000 -0500 CST Central Standard Time Civil Time -21600 -0600 MDT Mountain Daylight Time Civil Time -21600 -0600 MST Mountain Standard Time Civil Time -25200 -0700 PDT Pacific Daylight Time Civil Time -25200 -0700 PST Pacific Standard Time Civil Time -28800 -0800 The supported calendar types are: Calendar Calendar Name Type -------------------------------------------------------------- GREG Gregorian date Gregorian Calendar JD Julian Day Julian Day Number MJD Modified Julian Day Julian Day Number DAYS JD - 2450814.5 Julian Day Number DATE Date Gregorian Calendar PACK Packed date Gregorian Calendar DOY Day of year Gregorian Calendar OS Julian Calendar Julian Calendar ROMAN Roman calendar Roman Calendar RF French Rev. Calendar French Revolutionary Cal GSD Greenwich Sidereal Date Greenwich Sidereal Date GST Greenwich Sidereal Time Greenwich Sidereal Date TIME TIME(JD 2450814.5) Elapsed Seconds JEPOCH Julian Epoch Epoch BEPOCH Besselian Epoch Epoch
- JD/MJD/DAYS: For the JD, MJD and days calendars, enter a numeric value. Only Julian days between -2 x 10^9 and 2 x 10^9 are supported.
- GREG: There are a variety of formats for the GREG calendar. The standard is the words AD or BC followed by the year, month name, day, time of day. For example: AD 1993 Jun 30 23:59:50.234. The BC is mandatory, AD may be left off. Day 0 is the last day of the preceding month. Month numbers may be used instead of names. Colons may be omitted, replaced by spaces, or the letters h, m, s. Trailing information may be omitted, in such case, the earliest date is assumed. Further forms of imprecise and uncertain dates are supported: example: 1993 Jun 30 23:59? or 1990s?. Day of Year format is supported also: 1997 Day 104 14:20:32.
- DOY: Last three digits of the integral part is the day of the year, earlier digits are assumed to be the year.
- PACK: Last four digits are MM and DD, earlier digits assumed to be the year, if less then 100, 1900 automatically added.
- TIME: Elapsed time calendar, gives seconds since the zero point defined by the zero command. The default is Chandra time: the time tag on events in the Chandra data files, measured in seconds since 1998 Jan 1 00:00:0.0.
- GSD/GST: GSD is essentially JD(GMST). Calendar GSD outputs the result as JD and fraction of day. GST outputs the result as an integer day number and hh:mm:ss.sss of sidereal time.
See Also
- proposaltools
- colden, dates, obsvis, pimms, precess, prop-coords, prop-tools