Function hifitime::is_gregorian_valid

pub fn is_gregorian_valid(
    year: i32, 
    month: u8, 
    day: u8, 
    hour: u8, 
    minute: u8, 
    second: u8, 
    nanos: u32
) -> bool

Returns true if the provided Gregorian date is valid. Leap second days may have 60 seconds.