What's important is not the date of your SO, it's when your customer is supposed to receive his products. You should look into:

• customer lead times on customer form,
• delivery lead time on SO lines,
• supplier lead times on product forms > section Suppliers,
• company purchase lead time & security days on company form,
• delivery scheduled dates (ie. stock moves scheduled dates),
• and manufacturing lead times on product form (but apparently you don't manufacture).

OpenERP is calculating backwards when to procure based on all these lead times and dates to know when to start the whole procurement chain. And that can very well be in the future (if you are early in your operations like in your case), or in the past (if you are late).

Lead times is a sneaky topic because they are scattered all across the application in various places, and it couldn't be otherwise because they concern different aspects of the business. The only way to master them is really to know all of them and where they are. With the list above, I think you have a pretty comprehensive list. What you might want to do to understand how they behave is to reset them all to 0 and play around to see how each affects your procurement.

The quotation order date is determined as follow :

Expected Date in the generated procurment order = Sale Order Date (on the SO) + Customer Lead Time (on the SO line, coming from the product) - Security Days (on the company).

Expected Date = Expected Date in the generated procurment order - Purchase lead time ( in your company definition ---> configuration tab ).

Quotation Order Date = Expected Date - Delivery lead time ( in your product definition ---> procurment  tab --> choose any supplier ).