Looking At Calendar

Another usefull utility in LINUX is the “cal” command, which shows a simple calendar for the month of year specified

1. To confirm that 5 october 1993 is Tuesday, enter cal 10 93
root@hardy:/home/bearisusanto# cal 10 93
October 93
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 31

2. If you look closely, you’ll find that there’s a bit of a problem here. October 5 is shown as a Saturday rather than a Tuesday as expected.
The reason is that “cal” can list any year from A.D.0. In fact, what you have on your screen is how the month of October would have looked in A.D.93,1900.

Note :
This is a bit misleading because Western society uses the Julian calendar, adopted in 1752. Before that, the program should really list Gregorian format monthly calendars, but it can’t, so don’t use this as a historical reference for ascertaining what day of the week the Emperor Hadrian was born

3. To find out the information that you want, you’ll need to specify to the “cal” program both the month and full year:
root@hardy:/home/bearisusanto# cal 10 1993
October 1993
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
31

This is correct. The 5th of October in 1993 is indeed a Tuesday. On some systems, “cal” has no intelligent default action, so entering “cal” doesn’t simply list the monthly calendar for the current month. Later you’ll learn how to write a simple shell script to do just that. For now, turn to your system and enter “cal” to see what happens.

4. To show full calendar on a year

root@hardy:/home/bearisusanto# cal 2008
2008

January February March
Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa
1 2 3 4 5 1 2 1
6 7 8 9 10 11 12 3 4 5 6 7 8 9 2 3 4 5 6 7 8
13 14 15 16 17 18 19 10 11 12 13 14 15 16 9 10 11 12 13 14 15
20 21 22 23 24 25 26 17 18 19 20 21 22 23 16 17 18 19 20 21 22
27 28 29 30 31 24 25 26 27 28 29 23 24 25 26 27 28 29
30 31
April May June
Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa
1 2 3 4 5 1 2 3 1 2 3 4 5 6 7
6 7 8 9 10 11 12 4 5 6 7 8 9 10 8 9 10 11 12 13 14
13 14 15 16 17 18 19 11 12 13 14 15 16 17 15 16 17 18 19 20 21
20 21 22 23 24 25 26 18 19 20 21 22 23 24 22 23 24 25 26 27 28
27 28 29 30 25 26 27 28 29 30 31 29 30

July August September
Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa
1 2 3 4 5 1 2 1 2 3 4 5 6
6 7 8 9 10 11 12 3 4 5 6 7 8 9 7 8 9 10 11 12 13
13 14 15 16 17 18 19 10 11 12 13 14 15 16 14 15 16 17 18 19 20
20 21 22 23 24 25 26 17 18 19 20 21 22 23 21 22 23 24 25 26 27
27 28 29 30 31 24 25 26 27 28 29 30 28 29 30
31
October November December
Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa
1 2 3 4 1 1 2 3 4 5 6
5 6 7 8 9 10 11 2 3 4 5 6 7 8 7 8 9 10 11 12 13
12 13 14 15 16 17 18 9 10 11 12 13 14 15 14 15 16 17 18 19 20
19 20 21 22 23 24 25 16 17 18 19 20 21 22 21 22 23 24 25 26 27
26 27 28 29 30 31 23 24 25 26 27 28 29 28 29 30 31