I have this code
Calendar c = Calendar.getInstance();
c.set(Calendar.YEAR, year);
c.set(Calendar.MONTH, month - 1);
c.set(Calendar.DAY_OF_MONTH, 1);
When you get the c.get(Calendar.WEEK_OF_YEAR)
it produce different week number
example c.set(2016, Calendar.JANUARY, 1);
one android phone produce c.get(Calendar.WEEK_OF_YEAR)
= 1
and the other one is c.get(Calendar.WEEK_OF_YEAR)
= 53