I am trying to plot a graph with the time on the y-axis and days on the
x-axis..

The chart is suppose to plot the trends of when a process is completed -
this process includes 4 specific items. There are 4 daily tasks that are to
be completed daily and I want to be able to plot this completion time in a
chart so that the trends of when each item is usually completed can be noted.

Another problem with this graph is that one item is completed the night
before at 9PM but counts towards the next day's process and should actually
be counted as the "start" of the items being processed. (i.e. I want the 9PM
time from the previous day to appear at the bottom of the graph, and the
later 3 process times to appear above the "start" time)

Currently, the y-axis of my graph starts at 12:00AM and goes to 12:00AM and
goes to 4:48AM again (So the Y-axis actually spans over 24 hours..) Can you
please explain the logic behind how Excel chooses which "12:00AM" it uses to
plot the points.. and how I can change this y-axis to display times from the
previous nights and run into the day of the next day (i.e. 9PM from yesterday
to 9PM current day) and whether I will then have to adjust my data so that it
can be graphed at the appropriate 9PM (either yesterday or current day).

Thanks for your help!