google sheetsgoogle-sheets-charts
The settings for the vertical axis on a Google Sheets scatter plot provide an option for selecting or customizing a format for the labels, but no corresponding option is provided for the horizontal axis.
For example in the following chart, I have successfully changed the default decimal formatting on the vertical axes to integers, but can't change the "YYYY-MM-DD" formatting on the horizontal axis to simply "YYYY":
How do I format the horizontal axis labels on a Google Sheets scatter plot?
Adding a column for date and calculating the C values with:
=if(istext(D1),C2,D1+C2)
in D2 copied down a chart might be plotted of this Data Sheet1!A1:A4, Sheet1!D1:D4 with Use row 1 as headers:
Instead of using a Line chart use the Time Line Chart, named as Annotated time line in Chart types - Google Docs editors Help. The look and feel of this chart was not updated yet, but it still works and do a great job handling date-time labels for the horizontal axis.
Best Answer
Create a helper column (it can be adjacent to your your data, or anywhere else in your spreadsheet). Make the cell values = "Release Date" values, give the data a header, then format the data as YYYY.
If the column isn't adjacent to your data, create the chart without the X-Axis, then edit the Series to include both data sets, and edit the X-Axis to remove the existing range add a new range being your helper column range.