How can I find the blackout period for earnings releases for a company?

Are you referring to the time during which the company directors, officers ,and certain employees are not allowed to trade stock in the company? Blackout perdiods are set by company policy, so there is no hard and fast rule, but it often covers the period from 15 to 30 days prior to the end of the fiscal quarter through the day or two after the quarterly earnings announcement. Additional blackout periods are often added if the company has significant business dealings, such as a major acquisition, merger, etc. The SEC provdes a "safe harbor" that allows certain pre-arranged stock trades during the blackout period (for example, buying stock through an employee stock purchase plan). Since the details vary by company, probably the only way to find out for sure the dates of the blackout period is to ask the investor relations people at the company.