It's a new day, with a new lemony treat, for Girl Scout cookie sales in Southern Illinois.

Cookie sales in the Metro East start today — the first time in more than 20 years that the Girl Scouts of Southern Illinois will sell cookies in January; they've previously sold them in the fall. Girl Scouts of Eastern Missouri will begin selling cookies on Jan. 21.

This marks the 100th anniversary of Girl Scouting, which, of course, means a new cookie product. In addition to the usual array of cookies, including top seller Thin Mints, scouts in Illinois this year will offer Savannah Smiles, lemon wedge cookies dusted with confectioner's sugar. The name pays homage to Girl Scout founder Juliette Gordon Low, who was born in Savannah, Ga.

Tricia Higgins, a spokeswoman for the Girl Scouts of Southern Illinois, said cookie sales were moved to January this year because September and October are busy times for recruitment, registration and forming new troops.

She also said that "we were in a small percentage of councils that held their cookies sales" in the fall.

"The majority of councils hold their sales at this time of year, so we're able to benefit from the national branding and marketing that Girl Scouts USA does," Higgins said.

Donna Martin, chief executive of Girl Scouts of Eastern Missouri, said of the date move in Illinois: "We believe both sales will be very successful."

In Illinois, each box of cookies is $4 and will be delivered Feb. 13 to 16. On the Missouri side of the river, boxes will cost $3.50 and will be delivered Feb. 29 to March 18.

While the Missouri Scouts will have a slightly lower price to offer, they will not have Savannah Smiles on their side. Because the two groups use different cookie vendors, the new lemon cookies will not be available from Missouri Scouts. Still, they will have Lemonades, a lemon shortbread cookie introduced in 2006.