efficiently convert DateTime in long format (yyyyMMddHHmmss) into another zone for comparison

I have a long value that represents a datetime like this 20200319234500 (translates into March 19th, 2020 11:45:00PM)
I want this long value (20200319234500) converted into another timezone again in long format so I can do a greater than and less than comparison with the current date time in local timezone.

I want to do it efficiently so I dont have to create any objects during run time or do string creations after the start up.
but it looks like I must first convert long time to a string and then call ZonedDateTime.parse() function to get a datetime and then do a comparison. Is there another way of doing this?

 //This is known at compile time
        ZoneId baseZone = ZoneId.of("Europe/Paris");
        //This is known at compile time
        ZoneId localZone = ZoneId.of("America/New_York");
        //This is known at compile time
        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("uuuuMMddHHmmss").withZone(baseZone);

        long baseDateTime = 20210321234500L;

        //Dont want o be doing string operations. Is there a way to keep it in long and get another long in a different zone?
        ZonedDateTime convertedBaseDateTime  = ZonedDateTime.parse(Long.toString(baseDateTime), formatter);
        //Can I just get a long that represents current time in local zone? local zone is not JVM zone
        ZonedDateTime localDateTime = ZonedDateTime.now(localZone);
        //Thats the only operation I want to perform
        boolean result = convertedBaseDateTime.isBefore(  localDateTime);

You can do some maths to get the year, month, day, hour. minute, second from the long, and then you can pass it to ZonedDateTime.of

long baseDateTime = 20210321234500L;
int year = (int)(baseDateTime / 10000000000L);
int month = (int)(baseDateTime / 100000000L % 100);
int day = (int)(baseDateTime / 1000000L % 100);
int hour = (int)(baseDateTime / 10000L % 100);
int minute = (int)(baseDateTime / 100L % 100);
int second = (int)(baseDateTime % 100);
ZonedDateTime convertedBaseDateTime = ZonedDateTime.of(year, month, day, hour, minute, second, 0, baseZone);

This won't create new strings.

After that, notice that if you just want to check if a date time is before "now", you don't need a zone for "now". You just need to compare the numbers of (milli/nano)seconds since the epoch of then, and now.

// don't need these
// ZoneId localZone = ZoneId.of("America/New_York");
// ZonedDateTime localDateTime = ZonedDateTime.now(localZone);

// you just need to compare
convertedBaseDateTime.toEpochSecond() * 1000 < System.currentTimeMillis()

That said, if performance is so important for you, maybe you shouldn't use Java, and should instead use a more low-level language.

long baseDateTime = 20210321234500L;
LocalDateTime time=LocalDateTime.ofEpochSecond(baseDateTime /1000,0,ZoneOffset.ofHours(8));
//then you can use time2.isAfter() or some other methond to comparable that is link to jdk 8 API .