CAL(1)

NAME
cal - display a calendar

SYNOPSIS

cal [options] [[[day] month] year]

cal [options] [timestamp|monthname]

DESCRIPTION

cal displays a simple calendar. If no arguments are specified, the current month is displayed.

The month may be specified as a number (1-12), as a month name or as an abbreviated month name according to the current locales.

Two different calendar systems are used, Gregorian and Julian. These are nearly identical systems with Gregorian making a small adjustment to the frequency of leap years; this facilitates improved synchronization with solar events like the equinoxes. The Gregorian calendar reform was introduced in 1582, but its adoption continued up to 1923. By default cal uses the adoption date of 3 Sept 1752. From that date forward the Gregorian calendar is displayed; previous dates use the Julian calendar system. 11 days were removed at the time of adoption to bring the calendar in sync with solar events. So Sept 1752 has a mix of Julian and Gregorian dates by which the 2nd is followed by the 14th (the 3rd through the 13th are absent).

Optionally, either the proleptic Gregorian calendar or the Julian calendar may be used exclusively. See --reform below.

OPTIONS

-1, --one
    Display single month output. (This is the default.)

-3, --three
    Display three months spanning the date.

-n , --months number
    Display number of months, starting from the month containing the date.

-S, --span
    Display months spanning the date.

-s, --sunday
    Display Sunday as the first day of the week.

-m, --monday
    Display Monday as the first day of the week.

-v, --vertical
    Display using a vertical layout (aka ncal(1) mode).

--iso
    Display the proleptic Gregorian calendar exclusively. This option does not affect week numbers and the first day of the week. See --reform below.

-j, --julian
    Use day-of-year numbering for all calendars. These are also called ordinal days. Ordinal days range from 1 to 366. This option does not switch from the Gregorian to the Julian calendar system, that is controlled by the --reform option.

    Sometimes Gregorian calendars using ordinal dates are referred to as Julian calendars. This can be confusing due to the many date related conventions that use Julian in their name: (ordinal) julian date, julian (calendar) date, (astronomical) julian date, (modified) julian date, and more. This option is named julian, because ordinal days are identified as julian by the POSIX standard. However, be aware that cal also uses the Julian calendar system. See DESCRIPTION above.

--reform val
    This option sets the adoption date of the Gregorian calendar reform. Calendar dates previous to reform use the Julian calendar system. Calendar dates after reform use the Gregorian calendar system. The argument val can be:

        • 1752 - sets 3 September 1752 as the reform date (default). This is when the Gregorian calendar reform was adopted by the British Empire.

        • gregorian - display Gregorian calendars exclusively. This special placeholder sets the reform date below the smallest year that cal can use; meaning all calendar output uses the Gregorian calendar system. This is called the proleptic Gregorian calendar, because dates prior to the calendar system’s creation use extrapolated values.

        • iso - alias of gregorian. The ISO 8601 standard for the representation of dates and times in information interchange requires using the proleptic Gregorian calendar.

        • julian - display Julian calendars exclusively. This special placeholder sets the reform date above the largest year that cal can use; meaning all calendar output uses the Julian calendar system.

        See DESCRIPTION above.

-y, --year
    Display a calendar for the whole year.

-Y, --twelve
    Display a calendar for the next twelve months.

-w, --week[=number]
    Display week numbers in the calendar according to the US or ISO-8601 format. If a number is specified, the requested week will be printed in the desired or current year. The number may be overwritten if day and month are also specified.

    See the NOTES section for more details.

--color[=when]
    Colorize the output. The optional argument when can be auto, never or always. If the when argument is omitted, it defaults to auto. The colors can be disabled; for the current built-in default see the --help output. See also the COLORS section.

-c, --columns=columns
    Number of columns to use. auto uses as many as fit the terminal.

-h, --help
    Display help text and exit.

-V, --version
    Display version and exit.

PARAMETERS

Single digits-only parameter (e.g., 'cal 2020')
    Specifies the year to be displayed; note the year must be fully specified: cal 89 will not display a calendar for 1989.

Single string parameter (e.g., 'cal tomorrow' or 'cal August')
    Specifies timestamp or a month name (or abbreviated name) according to the current locales.

    The special placeholders are accepted when parsing timestamp, "now" may be used to refer to the current time, "today", "yesterday", "tomorrow" refer to of the current day, the day before or the next day, respectively.

    The relative date specifications are also accepted, in this case "+" is evaluated to the current time plus the specified time span. Correspondingly, a time span that is prefixed with "-" is evaluated to the current time minus the specified time span, for example '+2days'. Instead of prefixing the time span with "+" or "-", it may also be suffixed with a space and the word "left" or "ago" (for example '1 week ago').

Two parameters (e.g., 'cal 11 2020')
    Denote the month (1 - 12) and year.

Three parameters (e.g., 'cal 25 11 2020')
    Denote the day (1-31), month and year, and the day will be highlighted if the calendar is displayed on a terminal. If no parameters are specified, the current month’s calendar is displayed.

NOTES

A year starts on January 1. The first day of the week is determined by the locale or the --sunday and --monday options.

The week numbering depends on the choice of the first day of the week. If it is Sunday then the customary North American numbering is used, where 1 January is in week number 1. If it is Monday (-m) then the ISO 8601 standard week numbering is used, where the first Thursday is in week number 1.

COLORS

The output colorization is implemented by terminal-colors.d(5) functionality. Implicit coloring can be disabled by an empty file

    /etc/terminal-colors.d/cal.disable

for the cal command or for all tools by

    /etc/terminal-colors.d/disable

Since version 2.41, the $NO_COLOR environment variable is also supported to disable output colorization unless explicitly enabled by a command-line option.

The user-specific $XDG_CONFIG_HOME/terminal-colors.d or $HOME/.config/terminal-colors.d overrides the global setting.

Note that the output colorization may be enabled by default, and in this case terminal-colors.d directories do not have to exist yet.

The logical color names supported by cal are:

today
    The current day.

weeknumber
    The week number requested by the --week=<number> command line option.

weeks
    The number of the week.

header
    The header of a month.

workday
    Days that fall within the work-week.

weekend
    Days that fall outside the work-week.

For example:

    echo -e 'weekend 35\ntoday 1;41\nheader yellow' > $HOME/.config/terminal-colors.d/cal.scheme

HISTORY

A cal command appeared in Version 6 AT&T UNIX.

BUGS

The default cal output uses 3 September 1752 as the Gregorian calendar reform date. The historical reform dates for the other locales, including its introduction in October 1582, are not implemented.

Alternative calendars, such as the Umm al-Qura, the Solar Hijri, the Ge’ez, or the lunisolar Hindu, are not supported.

SEE ALSO

terminal-colors.d(5)

REPORTING BUGS

For bug reports, use the

AVAILABILITY

The cal command is part of the util-linux package which can be downloaded from