A common practice for generating a random token for a "forgot password" feature in PHP is to use the built-in functions random_bytes and bin2hex.
You can use the strtotime() function in PHP to convert a Unix timestamp to the beginning and end of that day.
In Java 8 and later, you can use the java.time.LocalDateTime class to represent a date and time without a time zone. To parse a date and time string into a LocalDateTime object, you can use the java.time.format.DateTimeFormatter class.
To get the current timestamp in string format in Java, you can use the SimpleDateFormat class and specify the desired format string.
You can use the DateTime class in PHP to find the time elapsed since a specific date time.