import java.time.Instant;
import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;
import java.time.format.DateTimeFormatterBuilder;
import java.util.Locale;

public class Main {
	public static void main(String[] args) {
		// Given date-time string
		String dateTimeString = "9/25/2020, 12:46:00 PM";

		DateTimeFormatter dtf = new DateTimeFormatterBuilder()
								.parseCaseInsensitive()
								.appendPattern("M/d/u, h:m:s a")
								.toFormatter(Locale.ENGLISH);

		// Convert the given date-time string to LocalDateTime
		LocalDateTime ldt = LocalDateTime.parse(dateTimeString, dtf);
		System.out.println(ldt);

		// Convert to LocalDateTime Instant if required
		Instant instant = ldt.toInstant(ZoneOffset.UTC);
		System.out.println(instant);
	}
}