Visualizing data over time

[deathbygraph]

Ok, so I have a logger that for some reason logs the date and time in different columns. I exported the data hoping to be able to graph it so I can see any trends over a 14 day period, but I can't seem to figure out how I can go about graphing it at all. Everything I have tried gives me either an impossible to read graph or has the dates completely wrong. The format of the excel spreadsheet is like below and goes on for about 22,000 rows (it logs every minute)



1 Date Time Output Reading
2 9/1/2016 11:58:00 8.8
3 9/1/2016 11:59:00 9.6
4 9/1/2016 12:00:00 6.6
5 9/1/2016 12:01:00 9.6
6 9/1/2016 12:02:00 10.6


If this isn't possible is there a formula I could use to prune it down to say ever 5-10 minutes ?

[MrShorty]

What have you tried? What do you prefer? I could see either option as possible (at least on the newer versions of Excel your profile indicates, some of the older versions have stricter limits on number of data points in a series and in a chart).

Are the date and time data actual dates/times, or are they text strings that look like dates/times? My first thought would be to
1) add a column combining date and time. should be as simple as A2+B2 if these are real date/time serial numbers. If they are text strings, there may need to be an additional function to convert text to date/time.
2) Plot this helper column (as xvalues) and the reading column (as yvalues) on an XY scatter chart (not a line chart).

If you want to prune the data down, a simple lookup function should work:
1) Add column to combine date+time as above
2) lookup values should be a function/entry that will create a column of date/time serial numbers incrementing by 5 or 10 minutes
3) xvalues will be a lookup function (like VLOOKUP()) that will search for lookup values in the main data table and return the corresponding date+time stamp (be sure to use TRUE for the 4th argument in the VLOOKUP() function
4) yvalues will be a similar lookup function.

Can I assume you know how to execute those steps? What parts do you get stuck on?

[deathbygraph]

They are currently actual date/time. Just tried to add them together (I didn't realize I could actually do that in itself so awesome!) and it is looking MUCH better now, thank you very much for the quick reply. Also, I will be pruning down the data so also thanks for including that.