Gantt Chart Half Days

Hello,

I am trying to create a gantt chart to display a construction schedule. We occasionally have tasks which take 12h, or half a day assuming 24h work.

My dataset recognizes that the task is only 12h. It starts at 7am and ends at 7pm, with the following task starting at 7pm and ending at 7am. So two tasks have been scheduled for one 24h block. See the "Calculated Scheduled Start/End Time" columns below. 

On the Gantt chart, each of these 12h tasks are being displayed as 24h, but maintaining the correct start times. As a result, the durations are incorrect and there is overlap between subsequent tasks ("Mobilize" and "Rig up"). Does the graphing component just have a minimum duration of one day? Is there any known workarounds for this? I would like to display this schedule accurately. 

Any help would be greatly appreciated.

Thanks