Does HourHalfBorderColor still works in new Calendar version ?

This property is obsolete now when CssOnly="false" mode is not supported anymore.

However, you can achieve this effect using CSS. The border is defined using a cell class. The default style ("calendar_default" theme) looks like this:

.calendar_default_cell_inner { position: absolute;top: 0px;left: 0px;bottom: 0px;right: 0px;border-right: 1px solid #ddd;border-bottom: 1px solid #ddd; background: #f9f9f9; }

Note the "border-bottom" style.

You can use BeforeCellRender to add a custom class to cells that separate cells inside an hour block:

protected void DayPilotCalendar1_BeforeCellRender(object sender, BeforeCellRenderEventArgs e)
{
  if (e.End.Minute > 0)
  {
      e.CssClass = "intrahour";
  }
}

<style>
    .intrahour .calendar_default_cell_inner {
        border-bottom: 1px solid red;
    }
</style>

Hi,
thank you for answer.
It works, great once more.