cal: command not found

The wonderful cal command can tell you a lot. Entered without any arguments, it shows you a calendar for the current month that looks like this:

$ cal
     April 2022
Su Mo Tu We Th Fr Sa
                1  2
 3  4  5  6  7  8  9
10 11 12 13 14 15 16
17 18 19 20 21 22 23
24 25 26 27 28 29 30

But there are several arguments you can add to the cal command to tell you even more. The Julian date, for example. Try this:

$ cal -j 1 2022

The example above produces a rather normal looking calendar, but the -j argument changes it from showing the day of the month (1-31 for January) to the Julian date, or day of the year, instead.

Of course for January, it’s hard to tell the difference. Try this:

$ cal -j 2 2022
       February 2022
 Su  Mo  Tu  We  Th  Fr  Sa
         32  33  34  35  36
 37  38  39  40  41  42  43
 44  45  46  47  48  49  50
 51  52  53  54  55  56  57
 58  59

If you encounter the below error while running the cal command:

cal: command not found

you may try installing the below package as per your choice of distribution:

cal Command Examples

1. To display the calender for 2011:

# cal 2011

2. To display single month output:

# cal -1

3. To display previous/current/next month output:

# cal -3

4. To display Sunday as a first day:

# cal -s

5. To display monday as a first day of the output:

# cal -m

6. To display the Julian dates:

# cal -j

7. To display the calender of current year:

# cal -y

8. To display the version information:

# cal -V

Final Thoughts

The cal command writes a Gregorian calendar to standard output. If you specify a four-digit year operand, a calendar for that year is written. If you specify no operands, a calendar for the current month is written. You can display a calendar for any month of any year by specifying the month, as a digit from 1 to 12, followed by any four-digit year up to 9999.