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Monthly Averages FAQ
How does Random Lengths calculate Monthly Averages from the weekly prices it reports?
From the Yearbook introduction: Under the ISO 8601 rule, the first week of the year is the week containing the first Thursday. In determining monthly averages, Random Lengths expands that rule, so the first week of a month is the week that contains the first Thursday of the month.
Random Lengths publishes an annual calendar, where the weeks are labeled in the Sunday column. You can use this calendar to follow how Random Lengths is determining which weeks fall in which month for the purpose of calculating the monthly averages.
The calendars are available to order in print format, or download online in PDF format at: