Fix cron range to be end inclusive

Range was supposed to including the limits.

Signed-off-by: Fredrik Lindberg <fli@shapeshifter.se>
Fix off-by-one tm_wday usage

tm_wday starts at 0, but the array of valid day expects that
1 is the first week day.

Signed-off-by: Fredrik Lindberg <fli@shapeshifter.se>