with c as
(
 select
  Date, Terminal_Id, LastTimeUpdate,
  row_number() over (order by 1/0) as rn
 from
  @Customers
)
select
 c.Date,
 isnull(c.Terminal_Id, substring(max(a.v1) over (order by rn rows between unbounded preceding and 1 preceding), 11, 1000000)),
 isnull(c.LastTimeUpdate, substring(max(a.v2) over (order by rn rows between unbounded preceding and 1 preceding), 11, 1000000))
from
 c cross apply
 (
  select
   str(rn, 10) + str(c.Terminal_Id, 10),
   str(rn, 10) + convert(varchar(30), c.LastTimeUpdate, 126)
 ) a (v1, v2)
order by
 rn;

with c as
(
 select
  Date, Terminal_Id, LastTimeUpdate,
  row_number() over (order by 1/0) as rn
 from
  @Customers
),
t1 (Date, TerminalId, LastTimeUpdate) as
(
 select
  c.Date,
  isnull(c.Terminal_Id, substring(max(a.v1) over (order by rn rows between unbounded preceding and 1 preceding), 11, 10000)),
  isnull(c.LastTimeUpdate, substring(max(a.v2) over (order by rn rows between unbounded preceding and 1 preceding), 11, 10000))
 from
  c cross apply
  (
   select
    str(rn, 10) + str(c.Terminal_Id, 10),
    str(rn, 10) + convert(varchar(30), c.LastTimeUpdate, 126)
  ) a (v1, v2)
),
t2 (Date, TerminalId, LastTimeUpdate, Date__next) as
(
 select
  Date, TerminalId, LastTimeUpdate,
  lead(Date, 1, dateadd(day, 1, Date)) over (partition by TerminalId order by Date) as Date__next
 from
  t1
)
select
 b.Date, b.TerminalId, b.LastTimeUpdate
from
 t2 t cross apply
 (
  select top (datediff(day, t.Date, t.Date__next))
   dateadd(day, row_number() over (order by 1/0) - 1, t.Date),
   t.TerminalId,
   t.LastTimeUpdate
  from
   master.dbo.spt_values
 ) b (Date, TerminalId, LastTimeUpdate)
order by
 t.TerminalId, b.Date;