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 --iso Display the proleptic Gregorian calendar exclusively. This
55 option does not affect week numbers and the first day of the
56 week. See --reform below.
57 -j, --julian
59 Use day-of-year numbering for all calendars. These are also
60 called ordinal days. Ordinal days range from 1 to 366. This
61 option does not switch from the Gregorian to the Julian calendar
62 system, that is controlled by the --reform option.
63 Sometimes Gregorian calendars using ordinal dates are referred
65 to as Julian calendars. This can be confusing due to the many
66 date related conventions that use Julian in their name: (ordi‐
67 nal) julian date, julian (calendar) date, (astronomical) julian
68 date, (modified) julian date, and more. This option is named
69 julian, because ordinal days are identified as julian by the
70 POSIX standard. However, be aware that cal also uses the Julian
71 calendar system. See DESCRIPTION above.
72 --reform val
74 This option sets the adoption date of the Gregorian calendar
75 reform. Calendar dates previous to reform use the Julian calen‐
76 dar system. Calendar dates after reform use the Gregorian cal‐
77 endar system. The argument val can be:
78 · 1752 - sets 3 September 1752 as the reform date (default).
80 This is when the Gregorian calendar reform was adopted by the
81 British Empire.
82 · gregorian - display Gregorian calendars exclusively. This
84 special placeholder sets the reform date below the smallest
85 year that cal can use; meaning all calendar output uses the
86 Gregorian calendar system. This is called the proleptic Gre‐
87 gorian calendar, because dates prior to the calendar system's
88 creation use extrapolated values.
89 · iso - alias of gregorian. The ISO 8601 standard for the rep‐
91 resentation of dates and times in information interchange
92 requires using the proleptic Gregorian calendar.
93 · julian - display Julian calendars exclusively. This special
95 placeholder sets the reform date above the largest year that
96 cal can use; meaning all calendar output uses the Julian cal‐
97 endar system.
98 See DESCRIPTION above.
100 -y, --year
102 Display a calendar for the whole year.
103 -Y, --twelve
105 Display a calendar for the next twelve months.
106 -w, --week[=number]
108 Display week numbers in the calendar (US or ISO-8601). See
109 NOTES section for more details.
110 --color[=when]
112 Colorize the output. The optional argument when can be auto,
113 never or always. If the when argument is omitted, it defaults
114 to auto. The colors can be disabled; for the current built-in
115 default see the --help output. See also the COLORS section.
116 -V, --version
118 Display version information and exit.
119 -h, --help
121 Display help text and exit.
122
124 Single digits-only parameter (e.g., 'cal 2020')
125 Specifies the year to be displayed; note the year must be fully
126 specified: cal 89 will not display a calendar for 1989.
127 Single string parameter (e.g., 'cal tomorrow' or 'cal August')
129 Specifies timestamp or a month name (or abbreviated name)
130 according to the current locales.
131 The special placeholders are accepted when parsing timestamp,
133 "now" may be used to refer to the current time, "today", "yes‐
134 terday", "tomorrow" refer to of the current day, the day before
135 or the next day, respectively.
136 The relative date specifications are also accepted, in this case
138 "+" is evaluated to the current time plus the specified time
139 span. Correspondingly, a time span that is prefixed with "-" is
140 evaluated to the current time minus the specified time span, for
141 example '+2days'. Instead of prefixing the time span with "+" or
142 "-", it may also be suffixed with a space and the word "left" or
143 "ago" (for example '1 week ago').
144 Two parameters (e.g., 'cal 11 2020')
146 Denote the month (1 - 12) and year.
147 Three parameters (e.g., 'cal 25 11 2020')
149 Denote the day (1-31), month and year, and the day will be high‐
150 lighted if the calendar is displayed on a terminal. If no
151 parameters are specified, the current month's calendar is dis‐
152 played.
153
155 A year starts on January 1. The first day of the week is determined by
156 the locale or the --sunday and --monday options.
157 The week numbering depends on the choice of the first day of the week.
159 If it is Sunday then the customary North American numbering is used,
160 where 1 January is in week number 1. If it is Monday (-m) then the ISO
161 8601 standard week numbering is used, where the first Thursday is in
162 week number 1.
163
165 Implicit coloring can be disabled as follows:
166 touch /etc/terminal-colors.d/cal.disable
168 See terminal-colors.d(5) for more details about colorization configura‐
170 tion.
171
173 The default cal output uses 3 September 1752 as the Gregorian calendar
174 reform date. The historical reform dates for the other locales,
175 including its introduction in October 1582, are not implemented.
176 Alternative calendars, such as the Umm al-Qura, the Solar Hijri, the
178 Ge'ez, or the lunisolar Hindu, are not supported.
179
181 A cal command appeared in Version 6 AT&T UNIX.
182
184 The cal command is part of the util-linux package and is available from
185 https://www.kernel.org/pub/linux/utils/util-linux/.
186util-linux January 2018 CAL(1)