Extracting datetime pattern from string based on culture

I have to extract datetime pattern from string date.

E.G. I have datetime string "2020.01.01-09:20" I parse this string using culture

var culture = new CultureInfo("en-us");
var date = "2020.01.01-09:20";
var isParsed = DateTime.TryParse(date, culture, DateTimeStyles.AdjustToUniversal, out var result);

Result is correct. Now I have to make some random changes in date and time and parse it back to string with pattern extracted from original string.

I make a method that contains all patterns for culture

private static IList<string> GetDateTimePatterns(CultureInfo culture)
{
    var info = culture.DateTimeFormat;
    return new string[]
    {
        info.FullDateTimePattern,
        info.LongDatePattern,
        info.LongTimePattern,
        info.ShortDatePattern,
        info.ShortTimePattern,
        info.MonthDayPattern,
        info.ShortDatePattern + " " + info.LongTimePattern,
        info.ShortDatePattern + " " + info.ShortTimePattern,
        info.YearMonthPattern,
        info.SortableDateTimePattern
    };
}

The result of

foreach (var pattern in GetDateTimePatterns(culture))
    {
        Console.WriteLine(result.ToString(pattern ,culture));
    }

generates output:

Wednesday, January 1, 2020 9:20:00 AM
Wednesday, January 1, 2020
9:20:00 AM
1/1/2020
9:20 AM
January 1
1/1/2020 9:20:00 AM
1/1/2020 9:20 AM
January 2020
2020-01-01T09:20:00

As you see there is no pattern that is the same as original string.

How to extract correct pattern depending on culture ?