\begin{tabular}{rclc}
yyyy: &  $x$, & $1\leq x\leq 200$, & $(+1900)$\\
mm: &  $y$, & $1\leq y\leq 12$, & \, \\
dd: & $z$, & $1\leq z\leq 31$, & \, \\
hh: & $u$, & $1\leq u\leq 24$, & \, \\
mm: & $v$, & $1\leq v\leq 60$, & \, \\
ss: & $t$, & $1\leq t\leq 24$, & \, \\
\end{tabular}