Graph showing sleep data

Question

Hi!
I have a task that would be easy to accomplish if I were to use a pen and paper, but still seems hard to accomplish in Numbers. I want to create a graph/diagram showing on the Y-axis: time of the day when (A) I went to bed, and (B) I woke up; and on the X-axis: date of that day. I have created a mockup chart showing how I (roughly) want my data to appear. Number's linear chart doesn't seem to accept "time/date" as a value for the Y-axis, so to plot this I had to use a graph diagram (which isn't really accurate):
The data I have is arranged in a three column table as following: [Date; Time lights out; Time out of bed (next morning)]
The reason the above chart isn't accurate is because I have entered all data as occuring on the same date (+1 if after midnight). If I hadn't, the Y-axis would just increase and increase for each night. And that's my problem: The time-data I want to enter shouldn't be date-specific on the Y-axis, only on the X-axis. Since this is part of a sleep-journal program, I will be making new entries each day (not all at once).
So, my question is: How do I avoid Numbers enterpreting these as consecutive dates and achive the chart I'm looking for?
Thank you,
Sebastian

Answer 1

I didn't look closely enough at your chart. Aside from the 24 hr problem, you cannot make a chart where the Y axis has a larger number on the bottom than on the top. You will hve to create your Y axis value labels manually.  Also, to get below "0:00", the chart cannot be plotting Date & Time values because there is no such thing as negative time.
I consider "sleep time" to be the ending of the day. From that viewpoint, it appears for each date you are entering the previous day's sleep time and the current day's wake time. The vertical distance between the two on the chart therefore indicates the amount of time you slept. I moved my columns around accordingly.
As explained above, I had to use durations like Jerry did.  Columns B, C, F, and G are formatted as durations.
You don't necessarily have to create three new columns. You really only need the one that adjusts the sleep time. But I find it much easier and less error prone and it often takes fewer steps to create charts when the data is all together. You can do it either way.
column E = A
column F = B- DURATION(,,IF(B>C,24,0))
column G = C
Make the scatter chart then do the following:
You need to set the Y-axis min and max, you cannot let them be "auto".  For the chart in the sceenshot, the max is 16h and the min is -4h and there are 5 steps.
Resize the chart to whatever size you want it to be.
The Y axis of the chart is actually a table. A plain table, one column. Type in the same Y axis labels that the chart made except for the lowest one which, in this case was a -4:00 and needed to be 20:00.
Turn off the chart's Y axis labels and position and resize the table to be the Y-axis labels.
Turn off the table borders and set the fill color to none.