diff options
Diffstat (limited to 'doc/clock.n')
| -rw-r--r-- | doc/clock.n | 34 |
1 files changed, 31 insertions, 3 deletions
diff --git a/doc/clock.n b/doc/clock.n index 0dae993..d75f32d 100644 --- a/doc/clock.n +++ b/doc/clock.n @@ -398,8 +398,12 @@ preprocessed format string. In order of preference: If the string contains a \fB%s\fR format group, representing seconds from the epoch, that group is used to determine the date. .IP [2] -If the string contains a \fB%J\fR format group, representing -the Julian Day Number, that group is used to determine the date. +If the string contains a \fB%J\fR, \fB%EJ\fR or \fB%Ej\fR format groups, +representing the Calendar or Astronomical Julian Day Number, that groups +are used to determine the date. +Note, that in case of \fB%EJ\fR or \fB%Ej\fR format groups, representing +the Julian Date with time fraction, this groups may be used to determine +the date and time. .IP [3] If the string contains a complete set of format groups specifying century, year, month, and day of month; century, year, and day of year; @@ -550,6 +554,30 @@ abbreviation appropriate to the current locale, and uses it to fix whether \fB%Y\fR refers to years before or after Year 1 of the Common Era. .TP +\fB%Ej\fR +On output, produces a string of digits giving the Astronomical Julian Date or +Astronomical Julian Day Number (JDN/JD). In opposite to calendar julian day +\fB%J\fR, it starts the day at noon. +On input, accepts a string of digits (or floating point with the time fraction) +and interprets it as an Astronomical Julian Day Number (JDN/JD). +The Astronomical Julian Date is a count of the number of calendar days +that have elapsed since 1 January, 4713 BCE of the proleptic +Julian calendar, which contains also the time fraktion (after floating point). +The epoch time of 1 January 1970 corresponds to Astronomical JDN 2440587.5. +This value corresponds the julian day used in sqlite-database, and is the same +as result of \fBselect julianday(:seconds, 'unixepoch')\fR. +.TP +\fB%EJ\fR +On output, produces a string of digits giving the Calendar Julian Date. +In opposite to julian day \fB%J\fR format group, it produces float number. +In opposite to astronomical julian day \fB%Ej\fR group, it starts at midnight. +On input, accepts a string of digits (or floating point with the time fraction) +and interprets it as a Calendar Julian Day Number. +The Calendar Julian Date is a count of the number of calendar days +that have elapsed since 1 January, 4713 BCE of the proleptic +Julian calendar, which contains also the time fraktion (after floating point). +The epoch time of 1 January 1970 corresponds to Astronomical JDN 2440588. +.TP \fB%Es\fR This affects similar to \fB%s\fR, but in opposition to \fB%s\fR it parses or formats local seconds (not the posix seconds). @@ -605,7 +633,7 @@ On output, produces a three-digit number giving the day of the year (001-366). On input, accepts such a number. .TP \fB%J\fR -On output, produces a string of digits giving the Julian Day Number. +On output, produces a string of digits giving the calendar Julian Day Number. On input, accepts a string of digits and interprets it as a Julian Day Number. The Julian Day Number is a count of the number of calendar days that have elapsed since 1 January, 4713 BCE of the proleptic |