Issue getting the days difference between future date and current date in java

Question

I need to pick a future date from calendar, suppose the date I am selecting is 04/30/2013. Now what I want is to send the date to server. At server end I need to calculate the number of days between the future date and current date and send it to database.

The problem is that when I do the calculation locally (because my server and browser are in same timezone) it works fine, but when the server is in a different timezone than the browser the difference in days does not come as expected. Someone please help me how to solve the timezone issues.

How do you send the date to the server? What format, I mean? — MaxArt, Apr 17 '13 at 09:24
Your question is not entirely clear to me: you are using javascript on the client side and java on your server ? — jeroen_de_schutter, Apr 17 '13 at 09:26
Well, you could simply pass the utc time to the server which generates the dates and calc the days between. — sk2212, Apr 17 '13 at 09:28

score 0 · Answer 1 · edited May 23 '17 at 10:25

To Offset for time differences

You should use a format to send the data that includes the timezone within it. You could:

Use UNIX time which does not use timezones (milliseconds since epoch) with GMT 00, and also use this on java side

see: Get current date/time in seconds

Use ISO-8601 which is a standard and can include the timezone as well of the browser, and then parse this server side:

see:

To Calculate the Difference (using MS and Calendar Object)

You need to use the calendar object. You create a calendar object and set with a future date: e.g. How to set Java.util.calendar to a specific time period in the future Then you can perform a calculation by subtracting the current date (as long) with the long returned by the calendar, and dividing by (1000*60*60*24).

Some code I used in my own application to find entries greater than a specific datetime (midnight):

long currentTimeStamp = System.currentTimeMillis();
Calendar cal;
cal = Calendar.getInstance();
cal.setTime(new Date(currentTimeStamp));

//GET MS OF MIDNIGHT FROM BEGINNING OF THE DAY
cal.set(Calendar.HOUR_OF_DAY, 0); cal.set(Calendar.MINUTE, 0); cal.set(Calendar.SECOND, 0); cal.set(Calendar.MILLISECOND,0);
long midnight = cal.getTimeInMillis();
if(currentTimeStamp - midnight > (30*24*60*60*1000))break;

score 0 · Answer 2 · answered Apr 17 '13 at 09:33

0

Convert both dates in one common timezone e.g. GMT and then calculate the difference.

answered Apr 17 '13 at 09:33

Lalit Chaudhari

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Issue getting the days difference between future date and current date in java

2 Answers2

To Offset for time differences

To Calculate the Difference (using MS and Calendar Object)