Try to Add to Trim like below..
Trim(maketime(RecNo()-1,0,0)) as Start,
Trim(maketime(RecNo()-1,59,59)) as End,
trim(mid(time(maketime(RecNo()-1),'h tt'),1,2)) & ' - ' & trim(time(maketime(mod(RecNo(),24)),'h tt')) as [Time Bucket]
Check the Attachment..
temp.qvw 165.5 K
These are probably caused by values that are either slightly more* than (for example) 8:59:59 and therefore fall into the 1 second gap between 98:59:59 and 09:00:00. You could reduce the size of the gaps to a much smaller value:
maketime(RecNo()-1,0,0) as Start,
Time(maketime(RecNo() - 1, 0, 0) - 1E-9) as End,
* this could be due to very small rounding errors caused by the date/time calculations.