Aid in making a clock code more modular
General comments

You should read the manual pages on time(), which gives you the time in seconds since 1970, library functions such as localtime, strftime and ctime that can be used to present time values and the sleep() function, which sleeps the process for a specified
  number of seconds.

Also:


variables and structure fields are normally not all-uppercase (X,Y,MIN)
put a single definition or expression on each line
leave a blank line between functions.
printf has many formatting options.  Of relevance here is the "%02d"
format string which prints an integer in 2 places, zero-padded if necessary

So for 1, it prints '01' and for 10 it prints '10'.
I prefer to see a space after while and if etc. and spaces around
operators (!=, %, / etc)
make all functions static where possible (in this program, all except
main)



- your function delay is not a good way of delaying, as it ties up the processor.  Better use sleep

Function showClock


I presume you wanted to call delay, but you didn't.  This function loops
continually using 100% of CPU time.  Better would be to use sleep() which
lets other processes run. So sleep(1) would sleep for 1 second.
using time() would be better than clock(), as you want intervals in
seconds
the single printf format "%02d:%02d:%02d" does what you want without pasing
three x-coordinates to the function
most of the rest is unnecessary if you use sleep and time and the other library functions to present the time interval