The left property (number) specifies the horizontal position of the modal dialog from the left edge in pixels. If not specified, the modal dialog is centered.
DayPilot.Modal.leftnullUse this property together with DayPilot.Modal.top to position the dialog explicitly.
const modal = new DayPilot.Modal({
left: 40,
top: 20,
// ...
});
modal.showUrl("/dialog.html");