Graphing swim times by stroke

The horizontal axis needs to be a date, preferably spaced out according to when the swim time occurred (not evenly based on data).

This kind of "value/date" axis is not available to any pivot chart. The first thing to understand is that, in order to get a date/value axis, you will need to create a regular chart from pivot data. Read through this (https://peltiertech.com/regular-char...-pivot-tables/ ) carefully, because you will need to be able to follow Peltier's instructions, as Excel is going to want to convert your chart to a pivot chart and you must do all you can to make sure it doesn't.

That said, it shoud be fairly straightforward. Your sample file did not include any of your attempts at creating a pivot table. I would expect a process like:

1) Create pivot table:
1a) Date as row label
1b) stroke as column label
1c) sum of time as the value field.
1d) If you make sure that Excel knows that the source data is a "table", then the pivot table's source data should automatically expand as you expand the table (https://www.dummies.com/software/mic...l-data-models/ ).

2) Create regular line chart from pivot table data using procedures from Peltier's tutorial. Format chart as desired (making sure that the horizontal axis is a date axis).

It should be that easy. Will that work for you? Where do you get stuck?

Problem 1: I don't know why the pivot table ignored the fractions of a second. I expect that somewhere inside of the pivot table's brain, it is programmed to ignore fractions of a second? Recognizing that times are just decimal numbers (representing fractions of a day), I changed the number format from time to general in column B of sheet1 (so those times show their full decimal number), then refreshed the pivot table. The fractions of a second reappeared in the pivot table. Probably need to do something so that the pivot table does not know that the source data in time (by changing number format or something).

Problem 2: The chart's data ranges only extended to row 22. In order to get the chart to see the expanding pivot table, I would probably delete the grand total row, then extend the data ranges for the chart to cover more rows than you will ever need? Will 100 rows be enough (define chart series to extend to row 100)?