All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
What should religiously be taken into account in determining the beginning of the month of Ramadan is two things: sighting the moon of Ramadan or completing the month of Sha'baan 30 days. However, astronomic calculations are not an acceptable means in determining the beginning of the month. Therefore, if the people of this country are not keen to sight the moon and rely on astronomic calculations in determining the beginning of the month, then you should not follow what they say. For more benefit, please refer to Fatwa 86669.
If there is a group of Muslims who are keen to sight the moon, then fast with them, and if you can sight the moon yourself, then do so. However, if you do not see it, and no other Muslim person sees it, then you should complete Sha'baan 30 days.
Allaah Knows best.