Validation in the scheduled tasks form prevents using more "complex" values using standard cron syntax.
- eval_cron_field($field, $min, $max)
- validate_fields($field, $value)
A valid hour value in "eval_cron_field" is "0-3,5-7", which is evaluated to to "0,1,2,3,5,6,7".
But the form for a scheduled task tells me the above is invalid syntax in "validate_fields".
It only allows simple syntax (commas XOR dashes).
- Extract regular expression constants for the cron syntax
- Use those constants in both instances