Kurt, if you are still checking in, here are some pointers on seasonality...
There are multiple sources of seasonality. Periods of several months based roughly on the climate and weather. There are recurring distortions, such as an annual holiday. There are seasonalities within weeks. Take the worst one for handling. Suppose you have a business that does a lot of its business on Saturdays (a bar perhaps). In order to compare periods properly, you need to determine how many Saturdays in the month. Suppose March last year had 5 Saturdays, and this year, March has only 4 Saturdays. The results for the month will be very different in comparing one year to the next. now if you are trying to determine what growth looks like year over year, if you do not take this into account, you will have a problem.
Deciding whether to use weeks or months is something you need to do up front. Many businesses make do just fine tracking seasonality on a monthly basis. Only if you have peculiar circumstances should you need to use weeks. The fact is that since most small businesses reporting systems are from accounting, and since accounting tends to use months, you are best to stick to months. In some businesses, though very few, every month has an equal share of the years sales. Most show some consistent variance. Now you are trying to model a retailer of sports related consumer items. All sports are seasonal (except perhaps swimming and workout gear). I would guess that if you are selling hockey gear, the season for retail would start about in September, show a peak in October, and decline around January, before completely dying in April. So instead of a straight 8.3% per month every month, you have 4 months without any sales. That means the average of the other months would be 100% divided by 8 months, or 12.5%. But we also are guessing that September is twice as good as the other months - (25%), while January is about 25% below average - (10%), and February through April is about 50% of normal - (6.25%). That leaves about 47% for October through November, more about 15.4% for each. Your seasonality would look like, from January through December, 10%, 6.25%, 6.25%, 6.25%, 0%, 0%, 0%, 0%, 25%, 15.4%, 15.4%, 15.4%.
Lastly, obviously each line of sports stuff will have a different seasonality curve - to check your numbers, check your sales of stuff last year if you have it broken down by product. If you don`t, check your purchases instead, and adjust for the inventory holding period.
It is important that you do this exercise, because it has a big impact on your cashflow, and since you are working on funding, the lender will want to know about seasonal fluctuations. You want them to know, too, since you don`t want them freaking out if you don`t sell a lot of water-skiiing gear in January.
Hope that helps.
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