date

No, you’re not asking the Terminal out with the date command. You’re simply asking what time and day it is.

$ date
Thu Mar  8 21:11:04 CST 2018

cal

Like date, you can print a calendar to the terminal with cal. The current date is highlighted.

$ cal
     March 2018       
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  

time

The time command can be used to give information about the time a command or process takes to run. It has a man page, which is kind of elusive on bash systems, as time is a builtin (within the shell) there.

If you want to figure out how long a command takes to execute (like scp, for example), you can use the following (where command is the command you’re testing). Bash shell on Ubuntu:

$ /usr/bin/time -p command
0.00user 0.00system 0:00.00elapsed 0%CPU (0avgtext+0avgdata 2432maxresident)k
0inputs+0outputs (0major+103minor)pagefaults 0swaps

Bash shell on Mac OSX:

$ /usr/bin/time -p command
---
        0.00 real         0.00 user         0.00 sys
$ time command
real	0m0.017s
user	0m0.003s
sys	0m0.008s