Hello.
There is no such native configuration but you are able to change the position of the datePicker popup manually after the editor opening. Something like:
grid.events.on("afterEditStart", function (id, col, colId, ev) { //event triggering for the cell edit
setTimeout(function () { //wait till the editor renders
var rect = document.querySelector(".dhx_cell-editor").getBoundingClientRect();//get the cell coordinates
el = document.querySelector(".dhx_popup") //get the calendar popUp element
el.style.left = rect.left + 'px'; //set the needed position
}, 50)
})
Here is the example:
https://snippet.dhtmlx.com/hh1v05z1