code: public static List<Long> createTimestampList(final long startUnixTimestamp,
                                                   final long endUnixTimestamp) {
          if (startUnixTimestamp > endUnixTimestamp) {
              return Collections.emptyList();
          }
  
          // normalize the start and end (next day's start)
          final long normStart = TimeModifier.START_OF_DAY.applyModifier(startUnixTimestamp);
          final long normEnd = TimeModifier.moveDays(endUnixTimestamp, true, 1);
  
          // determine which times we have to query for
          final List<Long> times = new ArrayList<>();
          for (long time = normStart; time < normEnd; time += 24 * 60 * 60) {
              times.add(time);
          }
  
          return times;
      }
docs: Creates a list of days between the specified start (inclusive) and end (inclusive).
  
  @param startUnixTimestamp the start
  @param endUnixTimestamp   the end
  
  @return the unix timestamps for each day between start and end