ANS nad RADB updates ?

Hello all,

  I'm sorry if this is a too stupid question, or if this is not the
appropiate forum to ask these kind of questions, but I'm a beginner on
that and still have a great lack of knowledge.
  I would like to know what are the days and hours that ANS, RADB or
other american organizations choose to update their database information
from RIPE Database.
  I need to know that in order to minimize the effect of a
BGP configuration change that also means a change in the RIPE Database.
  I'd highly appreciate any information on this point.

  Thanks a lot