How to Add a vertical Line to an Excel Chart to Mark an Event

[clemkonan]

Hello folks I am tracking the effect of using hormone disruption to control moths and I did 2 treatments, treatment 1 om May 12,2017 and treatment 2 November 17,2017.I want to mark off these 2 days on the chart so that the reader can see the effect of each treatment.
Month Year-2017
Jan 6,2017 0
Feb10,2017 1
Mar21,2017 1
Apr7,2017 4
Apr21,2017 13
May 11,2017 11
May 12,2017 10
May 26,2017 5
June2,2017 7
July 2,2017 2
Jul24,2017 3
Aug 2,2017 13
Aug 18,2017 15
Sept 8,2017 35
Sept 22,2017 13
Oct 6,2017 19
Oct 20,2017 27
Nov 10,2017 40
Nov 17,2017 30
Nov 22,2017 7
Dec 6,2017 11
Dec 14,2017 15
Dec 28,2017 9

Whats the simplest solution

 

[Gerald Higgins]

Hi.

There are a number of ways to do this.

One way is to use a separate chart data series that exists only to represent the marked dates.

Set up a column of data that contains zeroes for every date, and then contains some huge value for the two target dates.
You might prefer to use negative values instead of zeroes, just to make sure that they don't appear on the chart, and you might need to manually set the minimum value for the x axis to zero, or some other appropriate value.
You might also want to manually set a maximum value for the x axis.

Play around with this.