I am trying to get the display value for a date to be set in the format 'yyyy-MM-dd'. I have tried manipulating the 'String format' option on the control settings but with no luck. Any ideas?
The Format of the date displayed in the date control is dependent on the regional settings of the site collection. The string format field in the configuration only adjusts the format of the date in view mode. Entering the date will be in the default format but putting yyyy/MM/dd into the String format field in the configuration of the date control will display the date as you require but only in view mode of the form.