Why am I seeing blank squares on the hour-of-day reporting?

This article discusses why you may be seeing blank squares within your hour-of-day reporting.

Ui.Marketing dayparts all campaigns to serve between 5 AM and 12 AM (Midnight), which is based on the stated browser time of the end-users who are served impressions. Typically, there will not be any traffic served between midnight and 5 AM unless the specific daypart has been adjusted at the advertiser's request, or as an optimization to the campaign to increase reach.

Additionally, marketers will typically see lower traffic between 4 PM and 6 PM, as this represents 12 AM Midnight in UTC Time, which is when the reporting "day" changes over. Oftentimes most of the impressions have served in full for the "day" by this time.