O seguinte gera uma tabela de turnos. Não está exatamente claro o que você quer fazer, mas você deve ser capaz de fazer engenharia reversa determinando a mudança da data/hora de um evento usando alguns dos cálculos mostrados aqui.
EDITAR :Corrigido
case
para lidar com o padrão 2/2/3/2. ; with Samples as (
-- Start at the beginning of 2013.
select Cast( '01-01-2013 00:00' as DateTime ) as Sample
union all
-- Add hours up to the desired end date.
select DateAdd( hour, 1, Sample )
from Samples
where Sample <= '2013-01-30'
),
ExtendedSamples as (
-- Calculate the number of days since the beginning of the first shift on 1/1/2013.
select Sample, DateDiff( hour, '01-01-2013 07:00', Sample ) / 24 as Days
from Samples ),
Shifts as (
-- Calculate the shifts for each day.
select *,
case when ( Days + 1 ) % 9 in ( 0, 1, 4, 5 ) then 'C/D' else 'A/B' end as Shifts
from ExtendedSamples )
select *,
case when DatePart( hour, Sample ) between 7 and 18 then Substring( Shifts, 1, 1 ) else Substring( Shifts, 3, 1 ) end as Shift
from Shifts
option ( maxrecursion 0 )