Revert "Minor optimization for DateTimeType"
Revert "Minor optimization for DateTimeType"

This reverts commit 2d153f080c16483c8a44346b5ddfce1673263c5e. While
this minor optimization should have helped improve performance, but has
created subtle issues in at least one application.

Refs #9066

nrother/cakephp,ionas/cakephp,cakephp/cakephp,tenkoma/cakephp,thinkingmedia/cakephp,ADmad/cakephp,nrother/cakephp,berrygoudswaard/cakephp,CVO-Technologies/cakephp,mvdriel/cakephp,ADmad/cakephp,berrygoudswaard/cakephp,petteyg/cakephp,nrother/cakephp,CakeDC/cakephp,mvdriel/cakephp,garethellis36/cakephp,garethellis36/cakephp,HavokInspiration/cakephp,elboletaire/cakephp,dakota/cakephp,cakephp/cakephp,davidyell/cakephp,ndm2/cakephp,dakota/cakephp,cakephp-fr/cakephp,ndm2/cakephp,ndm2/cakephp,ADmad/cakephp,petteyg/cakephp,CakeDC/cakephp,ionas/cakephp,ndm2/cakephp,elboletaire/cakephp,garethellis36/cakephp,cakephp-fr/cakephp,cakephp/cakephp,elboletaire/cakephp,garethellis36/cakephp,petteyg/cakephp,davidyell/cakephp,cakephp-fr/cakephp,davidyell/cakephp,CVO-Technologies/cakephp,dakota/cakephp,HavokInspiration/cakephp,mvdriel/cakephp,cakephp/cakephp,HavokInspiration/cakephp,ADmad/cakephp,mvdriel/cakephp,tenkoma/cakephp,tenkoma/cakephp,CakeDC/cakephp,ionas/cakephp,petteyg/cakephp,tenkoma/cakephp,thinkingmedia/cakephp,thinkingmedia/cakephp,CakeDC/cakephp,CVO-Technologies/cakephp,dakota/cakephp,berrygoudswaard/cakephp