"We find that the moon really is new over Jerusalem each month by your calendar and is off as much as two days by the Jewish calendar. Therefore we wish to publish the truth - and we simply need a list of the moonrise after conjunction at Jerusalem. Brother Loughran just list them so that we can take the list straight to the printers."
To SBS this was valuable confirmation that, as far as a pre-printed calendar is concerned, the method we are using is reliable. We now invite any believer or group of believers in Jerusalem to check out the calendar SBS publishes against first sightings of the new moon with the naked eye. Please telephone SBS Scotland at 44-01560-483524 if you find that the starting date of the festival months of Abib or Ethanim as shown at Appendix A are incorrect.
The alternative to publishing a calendar in advance, is to post a lookout group at Jerusalem who would announce to the world - month by month - when the new moon is seen. This is still the best method of ensuring the correct starting dates of months. But we do not know of any group which does this on a monthly basis. To our knowledge they all publish their calendars and festival dates many months in advance; so they must all be using calculations of some sort.
Note: Many believers become polarized about the matter of keeping the correct Feast days. It is, of course, very important: and that is why SBS makes such an effort to get it right. But let no one forget that the Great Feasts ( the realities to which the current feasts merely point ) will be miraculously highlighted by signs in the sun, moon and stars! We will not then be dependant upon computer printout, or the knowledge and skill of leaders feverishly arguing amongst themselves as to who is correct. In the near future the sun and moon will clearly mark out the correct feasts, sacred seasons or sabbatical year just as they did when the Saviour hung on the cross. On that occasion the sun went out for three hours. That was no eclipse by any means; for an eclipse only lasts a few minutes. When the sun went out on that memorable day, even the Roman soldiers were staggered into saying "Truly this is the Son of God!" It will be the same in the near future; the promised signs in the sun, moon and stars will mark out the sacred times for all to see.
Having said that, it still behoves true believers to attend the sacred Feasts; because the Almighty God of Israel may well, as on that memorable Day of Pentecost long ago, have some extra ordinary gifts to bestow on His obedient people;
A Voice In The Wilderness Calendar Page The Almighty's Feast Days