Code shared from the Rust Playground

playground.rs

use bytes::Bytes;
use regex::bytes::Regex as BytesRegex;

fn main() {
    let val = b"2020-01-01";
    let my_regex = BytesRegex::new(r"\d{4}-(\d{2})-\d{2}").unwrap();
    let month = my_regex.captures(val).unwrap().get(1).unwrap();
    let month_digit = std::str::from_utf8(month.as_bytes()).unwrap().parse::<u8>().unwrap();
    println!("month smaller than 12: {}", month_digit<=12);
}