Coming up with logic to be able to add a time interval if the same date exists for the same clip#

Question

I am trying to separate out a clip if it has the same date. For example, since "Clip Number" 1 and 2 has the same date so I am trying to make the date different by adding a 6 hour interval. I would like to add a new field that is similar to the column "New Date"

Date	Clip_Number	New Date
1/2/2021	1	1/2/2021 0:00
1/2/2021	1	1/2/2021 0:00
1/2/2021	2	1/2/2021 6:00
1/2/2021	2	1/2/2021 6:00
1/3/2021	3	1/3/2021 0:00
1/3/2021	3	1/3/2021 0:00

Answer 1

Gordon solution works, but only if "there are only two values with the same date".

This solution works even in that case:

with data as (
select 1 clip, '2020-10-03' d
union all select 1, '2020-10-03'
union all select 1, '2020-10-03'
union all select 2, '2020-10-03'
union all select 2, '2020-10-03'
union all select 3, '2020-10-03'
union all select 3, '2020-10-04'
union all select 3, '2020-10-04'
)

select *
  , timestampadd('hour'
      , 6*(-1+dense_rank() over(partition by d order by clip))
      , d
    ) new_date
from data