1CAL(1) User Commands CAL(1)
2
6 cal - display a calendar
7
9 cal [options] [[[day] month] year]
10 cal [options] [timestamp|monthname]
11
13 cal displays a simple calendar. If no arguments are specified, the
14 current month is displayed.
15 The month may be specified as a number (1-12), as a month name or as an
17 abbreviated month name according to the current locales.
18 Two different calendar systems are used, Gregorian and Julian. These
20 are nearly identical systems with Gregorian making a small adjustment
21 to the frequency of leap years; this facilitates improved synchroniza‐
22 tion with solar events like the equinoxes. The Gregorian calendar
23 reform was introduced in 1582, but its adoption continued up to 1923.
24 By default cal uses the adoption date of 3 Sept 1752. From that date
25 forward the Gregorian calendar is displayed; previous dates use the
26 Julian calendar system. 11 days were removed at the time of adoption
27 to bring the calendar in sync with solar events. So Sept 1752 has a
28 mix of Julian and Gregorian dates by which the 2nd is followed by the
29 14th (the 3rd through the 13th are absent).
30 Optionally, either the proleptic Gregorian calendar or the Julian cal‐
32 endar may be used exclusively. See --reform below.
33
35 -1, --one
36 Display single month output. (This is the default.)
37 -3, --three
39 Display three months spanning the date.
40 -n , --months number
42 Display number of months, starting from the month containing the
43 date.
44 -S, --span
46 Display months spanning the date.
47 -s, --sunday
49 Display Sunday as the first day of the week.
50 -m, --monday
52 Display Monday as the first day of the week.
53 -v, --vertical
55 Display using a vertical layout (aka ncal mode).
56 --iso Display the proleptic Gregorian calendar exclusively. This
58 option does not affect week numbers and the first day of the
59 week. See --reform below.
60 -j, --julian
62 Use day-of-year numbering for all calendars. These are also
63 called ordinal days. Ordinal days range from 1 to 366. This
64 option does not switch from the Gregorian to the Julian calendar
65 system, that is controlled by the --reform option.
66 Sometimes Gregorian calendars using ordinal dates are referred
68 to as Julian calendars. This can be confusing due to the many
69 date related conventions that use Julian in their name: (ordi‐
70 nal) julian date, julian (calendar) date, (astronomical) julian
71 date, (modified) julian date, and more. This option is named
72 julian, because ordinal days are identified as julian by the
73 POSIX standard. However, be aware that cal also uses the Julian
74 calendar system. See DESCRIPTION above.
75 --reform val
77 This option sets the adoption date of the Gregorian calendar
78 reform. Calendar dates previous to reform use the Julian calen‐
79 dar system. Calendar dates after reform use the Gregorian cal‐
80 endar system. The argument val can be:
81 · 1752 - sets 3 September 1752 as the reform date (default).
83 This is when the Gregorian calendar reform was adopted by the
84 British Empire.
85 · gregorian - display Gregorian calendars exclusively. This
87 special placeholder sets the reform date below the smallest
88 year that cal can use; meaning all calendar output uses the
89 Gregorian calendar system. This is called the proleptic Gre‐
90 gorian calendar, because dates prior to the calendar system's
91 creation use extrapolated values.
92 · iso - alias of gregorian. The ISO 8601 standard for the rep‐
94 resentation of dates and times in information interchange
95 requires using the proleptic Gregorian calendar.
96 · julian - display Julian calendars exclusively. This special
98 placeholder sets the reform date above the largest year that
99 cal can use; meaning all calendar output uses the Julian cal‐
100 endar system.
101 See DESCRIPTION above.
103 -y, --year
105 Display a calendar for the whole year.
106 -Y, --twelve
108 Display a calendar for the next twelve months.
109 -w, --week[=number]
111 Display week numbers in the calendar (US or ISO-8601). See
112 NOTES section for more details.
113 --color[=when]
115 Colorize the output. The optional argument when can be auto,
116 never or always. If the when argument is omitted, it defaults
117 to auto. The colors can be disabled; for the current built-in
118 default see the --help output. See also the COLORS section.
119 -V, --version
121 Display version information and exit.
122 -h, --help
124 Display help text and exit.
125
127 Single digits-only parameter (e.g., 'cal 2020')
128 Specifies the year to be displayed; note the year must be fully
129 specified: cal 89 will not display a calendar for 1989.
130 Single string parameter (e.g., 'cal tomorrow' or 'cal August')
132 Specifies timestamp or a month name (or abbreviated name)
133 according to the current locales.
134 The special placeholders are accepted when parsing timestamp,
136 "now" may be used to refer to the current time, "today", "yes‐
137 terday", "tomorrow" refer to of the current day, the day before
138 or the next day, respectively.
139 The relative date specifications are also accepted, in this case
141 "+" is evaluated to the current time plus the specified time
142 span. Correspondingly, a time span that is prefixed with "-" is
143 evaluated to the current time minus the specified time span, for
144 example '+2days'. Instead of prefixing the time span with "+" or
145 "-", it may also be suffixed with a space and the word "left" or
146 "ago" (for example '1 week ago').
147 Two parameters (e.g., 'cal 11 2020')
149 Denote the month (1 - 12) and year.
150 Three parameters (e.g., 'cal 25 11 2020')
152 Denote the day (1-31), month and year, and the day will be high‐
153 lighted if the calendar is displayed on a terminal. If no
154 parameters are specified, the current month's calendar is dis‐
155 played.
156
158 A year starts on January 1. The first day of the week is determined by
159 the locale or the --sunday and --monday options.
160 The week numbering depends on the choice of the first day of the week.
162 If it is Sunday then the customary North American numbering is used,
163 where 1 January is in week number 1. If it is Monday (-m) then the ISO
164 8601 standard week numbering is used, where the first Thursday is in
165 week number 1.
166
168 Implicit coloring can be disabled as follows:
169 touch /etc/terminal-colors.d/cal.disable
171 See terminal-colors.d(5) for more details about colorization configura‐
173 tion.
174
176 A cal command appeared in Version 6 AT&T UNIX.
177
179 The default cal output uses 3 September 1752 as the Gregorian calendar
180 reform date. The historical reform dates for the other locales,
181 including its introduction in October 1582, are not implemented.
182 Alternative calendars, such as the Umm al-Qura, the Solar Hijri, the
184 Ge'ez, or the lunisolar Hindu, are not supported.
185
187 The cal command is part of the util-linux package and is available from
188 https://www.kernel.org/pub/linux/utils/util-linux/.
189util-linux January 2018 CAL(1)