ANNOTATION

Data Format
You can display one or more lines on your chart. Each row represents an X position on the chart—that is, a specific time; each line is described by a set of one to three columns.
The first column is of type date or datetime, and specifies the X value of the point on the chart. If this column is of type date (and not datetime) then the smallest time resolution on the X axis will be one day. Each data line is then described by a set of one to three additional columns as described here: Y value - [Required, Number] The first column in each set describes the value of the line at the corresponding time from the first column. The column label is displayed on the chart as the title of that line. Annotation title - [Optional, String] If a string column follows the value column, and the displayAnnotations option is true, this column holds a short title describing this point. For instance, if this line represents temperature in Brazil, and this point is a very high number, the title could be "Hottest day on record". Annotation text - [Optional string] If a second string column exists for this series, the cell value will be used as additional descriptive text for this point. You must set the option displayAnnotations to true to use this column. You can use HTML tags, if you set allowHtml to true; there is essentially no size limit, but note that excessively long entries might overflow the display section. You are not required to have this column even if you have an annotation title column for this point. The column label is not used by the chart. For example, if this were the hottest day on record point, you might say something like "Next closest day was 10 degrees cooler!".

annotationchart#example