AstronomicalCalendar has a problem with half hour timezones.

Java class AstronomicalCalendar is used by Zmanim Project
One of the users of Simple Luach Jewish calendar resides in Caracas, Venezuela.
This user reported a problem that day times are shown incorrectly – without half an hour difference.
The problem is that since 2007, Venezuela got timezone with -4.5 hours offset from GMT. I stated investigation on this issue and found that class AstronomicalCalendar incorrectly converts timezone offset. It rounds always to the lower number.

find the following function in the class:

just change gmtOffset from double to float: