According to a forum post, it looks like it's a bug in the DHTMLX scheduler itself. And I've tried several variants of the Viewport meta tag, such as:
<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=12.0, minimum-scale=.25, user-scalable=yes"/>
Nothing works, except if I pinch-zoom from the top area of the scheduler where the dates and column headers are shown:
Is it possible to alter via some jScript code to override any subsequent javascripting, and force pinch and zoom on the entire page?
Thanks