The Stack Overflow podcast is back! Listen to an interview with our new CEO.
1 of 5

Your data looks like an EventSeries to me. Therefore let's treat it like one.

es = EventSeries[data /. "x" -> Missing[], 
  MissingDataMethod -> {"Interpolation", InterpolationOrder -> 0}]

es["Path"]
{{978220800, 7.78}, {978307200, 5.}, {978393600, 5.}, {978480000, 5.}, {979516800, 5.}, 
 {979603200, 3.89}, {979689600, 3.89}, {979862400, 2.22}}