How do the comparative usage metrics work?

When looking at comparative usage statistics on a Monitor detail screen, the time periods for daily, weekly, and monthly statistics are defined below:

A day starts at midnight of the specified day. For example, the usage for Monday, March 12th starts at 12:00AM on Monday, March 12th, which is the minute after 11:59PM on Sunday, March 11th.

This time yesterday is defined the same way, just from the day before. However, the comparison is only made to the most recent completed hour - in this instance, the 2:00PM to 3:00PM hour. So at 3:45PM on Monday, March 12th, this time yesterday compares 12:00AM - 3:00PM on Monday, March 12th with the same time period from Sunday, March 11th.

A week starts at 12:00AM of the previous Sunday and goes to the following Saturday at 11:59PM. Under that specification, this week goes from 12:00AM of the most recent Sunday to the current minute of the current day.

This time last week compares this week to last week - that is, 12:00AM of the most recent Sunday to the most recent completed hour, compared to 12:00AM of the second-most recent Sunday to the same hour, just one week in the past. An example of this time last week is below:

• Today is Wednesday, March 14th and it is currently 3:30PM. This week is defined as 12:00AM on Sunday, March 11th to today, Wednesday, March 14th at 3:00PM because 2:00PM to 3:00PM is the most recently completed hour that flow data is available for.
• This time last week is defined as 12:00AM on Sunday, March 4th to Wednesday, March 7th at 3:00PM, even though it is currently 3:30PM because 2:00PM to 3:00PM is the most recently completed hour that flow data is available for.

This month is defined as 12:00AM of the first day of the month to 11:59PM of the last day of the month. For March, this would be 12:00AM on March 1st to 11:59PM on March 31st.

This time last month is defined as 12:00AM of the first day of the previous month to the same most recent completed hour as today, just one month in the past. On March 14th at 3:45PM, this would be 12:00AM on March 1st to the most recent completed hour (in this instance it is 3:00PM) on today, March 14th compared to the range from 12:00AM on February 1st to 3:00PM on February 14th.

However, if today were March 30th, these criteria would change slightly. Since February does not have a 30th day, this time last month would simply compare all of last month's days to the equivalent number of days of the current month, starting with the first day of the current month. In this instance, this time last month on March 30th would compare last month (12:00AM on February 1st to 11:59PM on February 28th assuming it's not a leap year) to this month (12:00AM on March 1st to 11:59PM on March 28th).