Question on Timing Subject Tests

Do schools care when you took subject tests, and specifically, is taking one of them 2.5 years before applying a negative in any way (assuming, ofcourse, you do well)? Also, if you report 2 subject tests, is the fact that you took them two years apart a problem in anyway?

Here is the situation. My son has just finished his freshman year and took pre-calc during the school year. Because Maths II does not include any material beyond pre-calc, he took the exam on saturday and apparently did well. He is – at this point – planning to apply to top engineering schools, and most likely will take Chemistry 2 years from now (he will take AP Chem in junior year, after finishing honors chem in sophomore year). He is planning to take Calculus AB, BC, and Ap Stats in next 2 years.

Is there any problem with reporting a subject test taken far back (and reporting two subject tests taken 2 years apart).