Yesterday marked the first day of Sunday liquor sales in Washington state, and the end of a pre-Prohibition “blue law” that banned all liquor sales on the Sabbath, when upstanding citizens were supposed to be in church. Three dozen stores, including three in Seattle, opened their doors yesterday across the state. Sunday sales, which are now legal in 33 states, are expected to generate more than $7 million in tax revenues over the next two years.