DateTime('2012-01-01') ignores timezone and DateTime('2012/01/01') does not ignore timezone. Since timezone is a must, change date delimiter from a dash to a slash.This change solves ERP5JS date search bug too.

Expected result of this fix is like this:

print context.portal_catalog(effective_date='2012-01-30', src__=1)

SELECT DISTINCT
   catalog.path,   catalog.uid    
FROM
      (
    catalog AS `catalog`
  INNER JOIN
    versioning AS `versioning`
  ON
    `versioning`.`uid` = `catalog`.`uid`
  )
  
WHERE 
  1 = 1 
  AND ((`versioning`.`effective_date` >= "2012-01-29 15:00:00"
  AND `versioning`.`effective_date` < "2012-01-30 15:00:00")
  AND (`catalog`.`viewable_owner` = 'zope'
  OR `catalog`.`security_uid` IN (17, 20, 23, 24, 25, 28, 29, 30, 31, 32, 33, 34, 35, 36, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51)))