The number of seconds between 2 Dates I have this method in Java:

private static int ConvertToTimestamp(Date value)
{
    DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.S", Locale.US);
    String text = "1970-01-01 00:00:00.0";
    LocalDateTime localDateTime = LocalDateTime.parse(text, formatter);

    // getTime() returns milliseconds
    int seconds = (int) (value.getTime()/1000) - localDateTime.getSecond();
    return seconds;

}


It returns the number of seconds between the input parameter and 1/1/1970.
Are there any improvements to this or better ways to do it?
value.getTime() returns the number of milliseconds since January 1, 1970, 00:00:00 GMT represented by a Date object.

You don't need a ConvertToTimestamp method, just call value.getTime() / 1000 to get the seconds.