This is a help page specific to using Dates online. For more information, please consult the CIAO Dates help page here.

Convert from Date System

Select the date system to convert from. The Dates GUI supports the following choices:

• Calendar Date - Gregorian Calendar Date
• Julian Date - Julian Day Number
• Modified Julian Date - Julian Day Number minus 2400000.5
• Day of Year - Day of Year for Gregorian Calendar Date
• Chandra Time - Seconds since the start of the Chandra Clock on January 1, 1998

Date

Input the date according to the following formats:

• Calendar Date - YYYY Mon DD [HH:MM:SS.SS] where "Mon" is the first three letters of the month name.
  The time of day is optional, and each successive field of the time of day is optional; that is, minutes, seconds, and fractional seconds are optional.
  • 1997 Sep 01
  • 1997 Jul 04 05:00:00.00

• Julian Date - XXXXXXX.XXXXXXXXXX
  When entering a Julian Date or Modified Julian Date, you may specify any number of decimal places, but the program truncates to 10 decimal places. Since this is a truncation and not a rounding, you may lose precision at the tenth decimal place. To get the maximum possible precision, you should round the input Julian Date or Modified Julian Date to 10 decimal places.
  • 1234567.1234567890
  The minimum acceptable input is 1721425.5 which corresponds to 0001 Jan 01 00:00:00.0

• Modified Julian Date - XXXXX.XXXXXXXXXX
  When entering a Julian Date or Modified Julian Date, you may specify any number of decimal places, but the program truncates to 10 decimal places. Since this is a truncation and not a rounding, you may lose precision at the tenth decimal place. To get the maximum possible precision, you should round the input Julian Date or Modified Julian Date to 10 decimal places.
  • 12345.1234567890
  The minimum acceptable input is -678575.0 which corresponds to 0001 Jan 01 00:00:00.0

• Day of Year - YYYYDDD[.DDDD]
  Day of Year for Gregorian Calendar Date

• Chandra Time - SSSSSSSS
  Seconds since the start of the Chandra clock on January 1, 1998

Results

Calendar Date, Julian Date, Modified Julian Date, Day of Year, and Chandra Time are displayed.

Notes

All dates and times are in Coordinated Universal Time (UTC). UTC is exactly:

• Eastern Daylight Time + 4 hours, or
• Eastern Standard Time + 5 hours, or
• Pacific Daylight Time + 7 hours, or
• Pacific Standard Time + 8 hours, or
• Greenwich Mean Time, or
• British Summer Time - 1 hour, etc.