@mikews,
The issue seems to be regarding the formatting of Date and Time. Please refer to this documentation page to format Date and Time.
Also, please refer to this stackoverflow link to parse Unix timestamp to javascript timestamp.
In case you are looking for something else, can you please create jsfiddle with sample JSON data reproducing the issue so that we can understand your requirement better and help you out.
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Indranil Deo,
Team CanvasJS