When you create one-minute or two-minute events, and with two-minute intervals between events, they overlap. The configuration used is below.
dp.days = 365;
dp.locale = "pt-br";
dp.scale = "Day";
dp.timeHeaders = [
{ groupBy: "Month", format: "yyyy" },
{ groupBy: "Day"},
];
dp.cellWidth = 80;
dp.rowMinHeight = 40;
// dp.cellDuration = 60;
dp.useEventBoxes = "Never";
dp.snapToGrid = false;
The evidence is in the image below: