Denny Cherry explains some of the oddities behind Azure billing:
Some things stand out to me when looking at this bill. First is the service that is being billed. It doesn’t say how many DWs we’re being billed more (more on that later).
Something else odd is that the SQL DW shows being billed for 1220 hours. Now in theory the most number of hours for any single service you can be billed for in a single month is 744 as that’s 24 (hours) *31 (days), but here we’re being billed for 1220 hours. Now we know for a fact that this SQL DW is powered off at times, so how are we using this resource for more than 31 days in a month?
The last oddity is the rate. $1.46 an hour. This points us to the reason for all of these strange numbers. That’s the rate to run a SQL DW at DW100 for one hour.
Click through for Denny’s explanation.