monthNameToNumber method
Converts a month abbreviation (e.g., 'JAN') to its numerical value (e.g., 1).
Implementation
int monthNameToNumber(String label) {
const months = [
'JAN',
'FEB',
'MAR',
'APR',
'MAY',
'JUN',
'JUL',
'AUG',
'SEP',
'OCT',
'NOV',
'DEC',
];
return months.indexOf(label) + 1;
}