populate same records into multiple based on hours spend.

let
    Source = Excel.CurrentWorkbook(){[Name="Table1"]}[Content],
    fx=(dt,et)=>List.Min({Time.EndOfHour(dt)-#duration(0,0,0,1),et}),
    DT=(ct,at)=>Duration.TotalHours(ct-at),
    Custom1 = Table.FromRecords(
                                List.TransformMany(
                                                   Table.ToRecords(Source),
                                                   each List.Generate(
                                                                      ()=>_&[
                                                                             CompleteTime=fx([AcceptTime],[CompleteTime]),
                                                                             DownTime=DT(CompleteTime,[AcceptTime])
                                                                            ],
                                                                      each [AcceptTime]<=[CompleteTime],
                                                                      (x)=>x&[
                                                                              AcceptTime=Time.StartOfHour(x[CompleteTime]+#duration(0,1,0,0)),
                                                                              CompleteTime=fx(AcceptTime,[CompleteTime]),
                                                                              DownTime=DT(CompleteTime,AcceptTime)]
                                                                     ),
                                                   (x,y)=>y
                                                  )
                               )
in
    Custom1

Hi hanuraolm ,

Please go to "Advanced Editor" dialog, and paste the wdx223_Daniel 's M syntax in it.

In your case, you may need to make some changes as shown below:

Best Regards,
Eyelyn Qin