How to allow JSON post (and later get) only "time" (not date/timestamp) property of resource

Creating API to allow JSON POST of "resource" with persistence to backend.

Have one of the property which is basically a "time" of the day (format 2.00 PM, 5.00 PM etc). Trying to explore various options of either passing it as plain String or text (from rest client) OR should be of any specific "time" format easy for api implementation to accept it(easy mapping/parsing). Looking for suggestions ?

Sample Json:

{

   "name" : "Mark",
   "age" : 15,
   "cutOffTime": "2.00 PM" (????)
   ........

}

Go for LocalTime

The modern date-time API which was first introduced with Java SE 8 and has been further enriched in the subsequent releases, provides a rich set of API to manage date, time and their formatting. Given below is a demo of the same:

import java.time.LocalTime;
import java.time.format.DateTimeFormatter;
import java.time.format.DateTimeFormatterBuilder;
import java.util.Locale;

public class Main {
	public static void main(String[] args) {
		// Test strings
		String[] strTimes = { "1:00", "01:00", "1:00 pm", "1:00 am", "01:00 am", "01:00 pm", "13:10", "8:9", "8:9 am" };

		// Define the formatter
		DateTimeFormatter inputFormatter = new DateTimeFormatterBuilder()
											.parseCaseInsensitive()
											.appendPattern("[h:m a][H:m]")
											.toFormatter(Locale.ENGLISH);

		DateTimeFormatter outputFormatter = DateTimeFormatter.ofPattern("HH:mm");

		for (String strTime : strTimes) {
			LocalTime time = LocalTime.parse(strTime, inputFormatter);

			// String to be displayed or saved into the database
			String formattedTime = time.format(outputFormatter);
			System.out.println(formattedTime);
		}
	}
}

Output:

01:00
01:00
13:00
01:00
01:00
13:00
13:10
08:09
08:09

It was error-prone as well as complex to do the same thing using the legacy date-time API. For your requirement, I recommend you use LocalTime (this is why I've chosen LocalTime in the demo). You can learn more about the modern date-time API from Trail: Date Time