5.4 Understanding Time Intervals

For all objectives except the Agreement objective, it is necessary to specify a time interval.

The time interval is the span of time during, which the objective measures and calculates values.

The interval can be 1 or more minutes or hours, 1 day, 1 week, or 1 month. The interval must be a positive number greater than zero. If specifying minutes, 60 must be evenly divisible by the specified number of minutes. For example, 5 minutes is valid, but 7 minutes is not. If the interval is hours, 24 must be evenly divisible by the specified number of hours. For example, 12 hours is valid, but 13 hours is not.

There are two considerations when setting the objective time interval:

5.4.1 Reporting Intervals

Objectives are usually created with a consideration of how the data needs to be reported. If you need to report on availability for the day, week, and month, you could create three different objectives. However, this could result in creating many objectives, which might be confusing when reviewing agreements.

In its reporting capability, Operations Center has an option to select a smaller interval than the one used for the objective. For example, assume an objective is defined using the month interval. When viewing an SLA Status report in the Operations Center dashboard, you can view the availability for a week or day.

5.4.2 Aligned vs. Rolling

Aligned objectives automatically reset when the specified interval completes. For instance, to look at performance for each month, starting at the beginning of the calendar month (the 1st) and ending with the last calendar day of that month, set the interval to 1 month aligned. The objective resets at the beginning of each month. Other aligned objective examples include:

  • 1 hour aligned starts at 12:00 and resets at 1:00

  • 1 day aligned starts on March 1st at 12:00 AM and resets on March 2nd at 12:00 AM

  • 1 week aligned starts on Sunday at 12:00 AM and resets on the next Sunday at 12:00 AM

  • 1 month aligned starts on March 1st at 12:00 AM and resets on April 1st at 12:00 AM

Rolling objectives are currently not supported.

Unlike aligned intervals, rolling objectives are continuously evaluated for a specified interval of time. Therefore, to always view the last 24 hours, set the interval to 24 hours rolling, which starts at the present time and ends 24 hours earlier. Rolling objectives reset only when the interval no longer includes conditions that cause the objective to fail. For example, if the service availability is 94.8% for the last 24 hours because of an outage that occurred May 28, from 10:11 AM to 11:26 AM, then the availability objective resets after May 29, 11:26 AM.

5.4.3 Customizing the Weekly Time Interval

By default, the time interval for week starts on Sunday. This can be configured to start on Monday if required.

To customize the start of the week interval:

  1. In a text editor, open the /OperationsCenter_install_path/config/Formula.custom.properties file.

  2. To set the time window to start on Monday, add the following parameter:


    Setting this parameter to true reverts behavior back to the default of Sunday being the first day of the week.

  3. Stop and restart the Operations Center server for the changes to take effect.

For information on creating and editing the Formula.custom.properties file, see Making Custom Changes in the Operations Center 5.6 Server Configuration Guide