When in the cell cycle is the number of chromosomes normally reduced?
It is the other way around. Meiosis I (or reductional division) splits chromosome pairs so each cell gets half of the chromosomes of the parent. Meiosis II (or equational division) splits double-chromatid chromosomes (making two single-chromatid chromosomes), so cells retain the number of chromosomes, like in mitosis.



If more clarification needed:


before the S phase: 23 pairs of chromosomes, 46 single-chromatid
chromosomes 
before the meiosis I: 23 pairs of chromosomes, 46
double-chromatid chromosomes
before the meiosis II: 23
double-chromatid chromosomes without their homologous other
after the
meiosis II: 23 single-chromatid chromosomes without their homologous
other
after fertilization = before the S phase


(I'm talking about humans here.)