What was the dates on the rocks in Bud Not Buddy?

On the rocks Herman E. Calloway has it reads

-Idlewild M. 5/2/36

-Preston In. 6/4/36

And Chicago Il. 3/19/32

On Bud's rocks that he got from his momma, Angela Janet Caldwell née Calloway they read

Kentland Ill. 5/10/11

Loogootee in. 5/16/11

Sturgis m. 8/30/12

Gary in. 6/13/12

And Flint m. 8/11/11

(ps. Née means originally called. So née Calloway means her maiden name or before she was married.)