BUG: Fix bad dates from test factory.
BUG: Fix bad dates from test factory.

Passing the exchange time timestamp to is_market_hours was ending
up with odd behavior due to conversion back to UTC when checking
the is_trading_day boolean.

DVegaCapital/zipline,bartosh/zipline,AlirezaShahabi/zipline,keir-rex/zipline,bartosh/zipline,enigmampc/catalyst,davidastephens/zipline,chrjxj/zipline,nborggren/zipline,iamkingmaker/zipline,umuzungu/zipline,wilsonkichoi/zipline,CarterBain/AlephNull,ChinaQuants/zipline,humdings/zipline,Scapogo/zipline,aajtodd/zipline,euri10/zipline,morrisonwudi/zipline,YuepengGuo/zipline,cmorgan/zipline,aajtodd/zipline,wubr2000/zipline,michaeljohnbennett/zipline,erikness/AlephOne,dmitriz/zipline,stkubr/zipline,jimgoo/zipline-fork,AlirezaShahabi/zipline,ronalcc/zipline,mattcaldwell/zipline,cmorgan/zipline,jordancheah/zipline,StratsOn/zipline,joequant/zipline,euri10/zipline,wilsonkichoi/zipline,florentchandelier/zipline,MonoCloud/zipline,semio/zipline,otmaneJai/Zipline,semio/zipline,MonoCloud/zipline,CDSFinance/zipline,erikness/AlephOne,grundgruen/zipline,kmather73/zipline,YuepengGuo/zipline,CDSFinance/zipline,davidastephens/zipline,humdings/zipline,keir-rex/zipline,dkushner/zipline,quantopian/zipline,magne-max/zipline-ja,otmaneJai/Zipline,StratsOn/zipline,kmather73/zipline,sketchytechky/zipline,magne-max/zipline-ja,florentchandelier/zipline,dkushner/zipline,jordancheah/zipline,CarterBain/AlephNull,gwulfs/zipline,michaeljohnbennett/zipline,alphaBenj/zipline,DVegaCapital/zipline,dmitriz/zipline,zhoulingjun/zipline,gwulfs/zipline,ronalcc/zipline,sketchytechky/zipline,alphaBenj/zipline,enigmampc/catalyst,morrisonwudi/zipline,dhruvparamhans/zipline,chrjxj/zipline,grundgruen/zipline,jimgoo/zipline-fork,umuzungu/zipline,dhruvparamhans/zipline,stkubr/zipline,zhoulingjun/zipline,Scapogo/zipline,wubr2000/zipline,ChinaQuants/zipline,joequant/zipline,quantopian/zipline,nborggren/zipline,mattcaldwell/zipline,iamkingmaker/zipline