declare @trans table (
  dt datetime not null,
  amount money not null
)

insert @trans
  select '1/1/2020 10:43', 10.23
  union
  select '1/1/2020 23:07', 100
  union
  select '1/2/2020 9:19', 980
  union
  select '1/3/2020 15:13', 100500
  union
  select '9/8/1973 9:00', 777

;with
time_points as (select distinct dt from @trans),
aggregated_sums as (
select time_points.dt, sum(t.amount) amount from
  time_points cross join @trans t
  where t.dt between dateadd(HH, -24, time_points.dt) and time_points.dt
  group by time_points.dt
  having sum(t.amount) > 1000
)
select cast(dt as date) from aggregated_sums