Do I have to enter US within certain date to keep my US visa valid? Like the Canadian Landing Paper? + Y7 I" S) S5 O7 P- w" _ ; |6 d3 U- x* q N+ bI did not see that on the visa. Or maybe I missed it. * n4 q y9 d: c# |* v" v2 w o7 d* @' y& H" ^* ?3 }1 N