Combine date ranges for rows with same value

Data Looks Like Below – my desired output is that when the next entry in the day is the same value those times are combined to get a total time. Once a value changes, take the date of the first entry (of that value) to the new value so that we get the combined time that value lasted.

    Value            Date
60                  1/5/2019 8:00
60                  1/5/2019 9:00
60                  1/5/2019 10:00
75                  1/5/2019 10:30
60                  1/5/2019  11:00
40                  1/5/2019  12:00
40                  1/5/2019  13:00

Desired Output

    Value            Total Time
60                  1/5/2019 8:00 - 10:30 = 2 and a half hours
75                  1/5/2019 10:30 - 11:00 = half hour
60                  1/5/2019  11:00 - 12:00 = 1 hour
40                  1/5/2019  12:00 - 13:00 = 1 hour

Answer

This is a gaps and islands problem. For this version, I think the difference of row numbers is the simplest solution. So, this almost solves your problem:

select value, min(date), max(date)
from (select t.*,
             row_number() over (order by date) as seqnum,
             row_number() over (partition by value order by date) as seqnum_v
      from t
     ) t
group by (seqnum - seqnum_v), value;

But you want the next start, so we need a lead() as well:

select value, min(date) as startdate,
       lead(min(date), 1, max(date)) over (order by min(date)) as enddate
from (select t.*,
             row_number() over (order by date) as seqnum,
             row_number() over (partition by value order by date) as seqnum_v
      from t
     ) t
group by (seqnum - seqnum_v), value;

And to get the total time:

select value,
       datediff(minute,
                min(date),
                lead(min(date), 1, max(date)) over (order by min(date))
               ) as dur_minutes
from (select t.*,
             row_number() over (order by date) as seqnum,
             row_number() over (partition by value order by date) as seqnum_v
      from t
     ) t
group by (seqnum - seqnum_v), value;