jcal
Display a calendar in the terminal
TLDR
Display a calendar for the current month
Display the previous, current, and next months
Display a calendar for a specific year (4 digits)
Display a calendar for a specific month and year
SYNOPSIS
jcal [-jy] [[[month] year]]
PARAMETERS
-j
Display Julian dates (default).
-y
Display the entire year.
month
The month to display (1-12). If omitted, the current month is shown.
year
The year to display. If omitted, the current year is shown.
DESCRIPTION
The jcal
command is a simple utility in Linux systems, similar to the standard cal
command, but it displays Julian dates alongside the standard Gregorian calendar. Julian dates represent the number of days elapsed since a specific epoch (usually January 1, 4713 BC in the Julian proleptic calendar). jcal
can be used to show the current month's calendar, a specific month and year, or an entire year. It is useful for those who work with Julian dates for scientific, astronomical, or historical purposes.
Its basic function is to output a human-readable calendar representation, making it easier to relate Gregorian dates to their corresponding Julian date equivalents. It helps bridge the gap between standard calendar usage and contexts where Julian date representation is necessary or preferred. The user can choose to display a single month or the entire year's calendars.
EXAMPLES
jcal
: Display the current month's calendar with Julian dates.
jcal 1 2024
: Display January 2024's calendar with Julian dates.
jcal -y 2024
: Display the entire year of 2024's calendar with Julian dates.
HISTORY
jcal
is a derivative of the standard cal
utility, modified to include the display of Julian dates. Its development likely stemmed from the need to easily correlate Gregorian calendar dates with their Julian day number equivalents, commonly used in scientific fields. Its usage has been mostly consistent, serving as a straightforward command for presenting calendar information with Julian date extensions.