Julian Day Count

A count of days since BCE 4713 Jan 01 12:00:00 UTC Julian (proleptic). Yes, that’s noon. This calendar system is used mostly for astronomy purposes, though there is a modified variant with a narrower scope which counts from midnight instead.

Calendar Name:

jdc

Supported Input Types:

  • string

  • integer

  • arbitrary-precision floating point number of seconds

Supported Format Strings:

  • full - the full, canonical Day Count

  • fullday - the full Day Count, without the fractional time part

  • fulltime - just the fractional time part of the full Day Count

  • modified - an abbreviated Day Count, 2400000.5 less than the full (starts at midnight instead of noon)

  • day - the modified Day Count, without the fractional time part

  • time - just the fractional time part of the modified Day Count

Offsets:

  • number of days, as integer or float, via numeric or string types

    • can include fractional days to indicate time