State Problem

[jhaubrich]

sdate, edate, and delta need to always represent the valid values in the input boxes.

Perhaps the best solution would be to not keep copies of those values in variables, rather query the input boxes whenever a value is needed.

Scenario: A plot is live updating and overwriting the date values in the input boxes to reflect the new data's date range. The aparent state wouldn't represent dateRangers internal state, and editing a date value would produce unpredictable range calculations.