date_trunc also accepts 'quarter'.  Noted by Yoshihisa Nakano.
date_trunc also accepts 'quarter'.  Noted by Yoshihisa Nakano.

ovr/postgres-xl,rvs/gpdb,Chibin/gpdb,randomtask1155/gpdb,cjcjameson/gpdb,kmjungersen/PostgresXL,ashwinstar/gpdb,lpetrov-pivotal/gpdb,randomtask1155/gpdb,lpetrov-pivotal/gpdb,CraigHarris/gpdb,yuanzhao/gpdb,jmcatamney/gpdb,atris/gpdb,edespino/gpdb,ahachete/gpdb,janebeckman/gpdb,foyzur/gpdb,tangp3/gpdb,arcivanov/postgres-xl,foyzur/gpdb,postmind-net/postgres-xl,janebeckman/gpdb,pavanvd/postgres-xl,techdragon/Postgres-XL,CraigHarris/gpdb,cjcjameson/gpdb,xuegang/gpdb,janebeckman/gpdb,lintzc/gpdb,rubikloud/gpdb,chrishajas/gpdb,rvs/gpdb,xuegang/gpdb,randomtask1155/gpdb,techdragon/Postgres-XL,adam8157/gpdb,arcivanov/postgres-xl,atris/gpdb,foyzur/gpdb,50wu/gpdb,edespino/gpdb,zaksoup/gpdb,Quikling/gpdb,CraigHarris/gpdb,edespino/gpdb,greenplum-db/gpdb,rvs/gpdb,chrishajas/gpdb,yuanzhao/gpdb,chrishajas/gpdb,rubikloud/gpdb,0x0FFF/gpdb,chrishajas/gpdb,cjcjameson/gpdb,tangp3/gpdb,adam8157/gpdb,50wu/gpdb,ahachete/gpdb,zeroae/postgres-xl,0x0FFF/gpdb,0x0FFF/gpdb,ashwinstar/gpdb,royc1/gpdb,CraigHarris/gpdb,CraigHarris/gpdb,edespino/gpdb,yuanzhao/gpdb,greenplum-db/gpdb,atris/gpdb,rubikloud/gpdb,Chibin/gpdb,rubikloud/gpdb,xuegang/gpdb,lpetrov-pivotal/gpdb,xinzweb/gpdb,rvs/gpdb,royc1/gpdb,Chibin/gpdb,Chibin/gpdb,jmcatamney/gpdb,ahachete/gpdb,cjcjameson/gpdb,ovr/postgres-xl,lintzc/gpdb,edespino/gpdb,janebeckman/gpdb,xuegang/gpdb,cjcjameson/gpdb,randomtask1155/gpdb,kaknikhil/gpdb,foyzur/gpdb,tangp3/gpdb,greenplum-db/gpdb,Chibin/gpdb,atris/gpdb,janebeckman/gpdb,xuegang/gpdb,tpostgres-projects/tPostgres,kaknikhil/gpdb,tangp3/gpdb,kmjungersen/PostgresXL,snaga/postgres-xl,royc1/gpdb,zeroae/postgres-xl,randomtask1155/gpdb,tangp3/gpdb,tangp3/gpdb,0x0FFF/gpdb,zaksoup/gpdb,tpostgres-projects/tPostgres,Chibin/gpdb,pavanvd/postgres-xl,yazun/postgres-xl,janebeckman/gpdb,cjcjameson/gpdb,xinzweb/gpdb,jmcatamney/gpdb,edespino/gpdb,oberstet/postgres-xl,xinzweb/gpdb,Postgres-XL/Postgres-XL,chrishajas/gpdb,royc1/gpdb,lisakowen/gpdb,kaknikhil/gpdb,lintzc/gpdb,tangp3/gpdb,kaknikhil/gpdb,Quikling/gpdb,0x0FFF/gpdb,Postgres-XL/Postgres-XL,oberstet/postgres-xl,postmind-net/postgres-xl,edespino/gpdb,snaga/postgres-xl,royc1/gpdb,rvs/gpdb,ovr/postgres-xl,Quikling/gpdb,yuanzhao/gpdb,tpostgres-projects/tPostgres,zeroae/postgres-xl,kaknikhil/gpdb,lisakowen/gpdb,Chibin/gpdb,adam8157/gpdb,rubikloud/gpdb,kaknikhil/gpdb,ahachete/gpdb,lpetrov-pivotal/gpdb,xuegang/gpdb,ashwinstar/gpdb,lintzc/gpdb,CraigHarris/gpdb,Chibin/gpdb,rvs/gpdb,CraigHarris/gpdb,jmcatamney/gpdb,foyzur/gpdb,zeroae/postgres-xl,rubikloud/gpdb,greenplum-db/gpdb,kmjungersen/PostgresXL,lisakowen/gpdb,jmcatamney/gpdb,jmcatamney/gpdb,50wu/gpdb,ashwinstar/gpdb,Quikling/gpdb,tangp3/gpdb,Chibin/gpdb,randomtask1155/gpdb,lpetrov-pivotal/gpdb,chrishajas/gpdb,edespino/gpdb,xuegang/gpdb,Postgres-XL/Postgres-XL,cjcjameson/gpdb,yuanzhao/gpdb,ashwinstar/gpdb,snaga/postgres-xl,Quikling/gpdb,kaknikhil/gpdb,pavanvd/postgres-xl,lintzc/gpdb,arcivanov/postgres-xl,Postgres-XL/Postgres-XL,greenplum-db/gpdb,greenplum-db/gpdb,ovr/postgres-xl,lisakowen/gpdb,yazun/postgres-xl,techdragon/Postgres-XL,yuanzhao/gpdb,janebeckman/gpdb,lintzc/gpdb,adam8157/gpdb,oberstet/postgres-xl,Quikling/gpdb,CraigHarris/gpdb,rvs/gpdb,chrishajas/gpdb,yazun/postgres-xl,ashwinstar/gpdb,xinzweb/gpdb,tpostgres-projects/tPostgres,chrishajas/gpdb,greenplum-db/gpdb,janebeckman/gpdb,ashwinstar/gpdb,xinzweb/gpdb,yuanzhao/gpdb,50wu/gpdb,ahachete/gpdb,xinzweb/gpdb,edespino/gpdb,royc1/gpdb,lpetrov-pivotal/gpdb,0x0FFF/gpdb,postmind-net/postgres-xl,rubikloud/gpdb,yuanzhao/gpdb,0x0FFF/gpdb,xinzweb/gpdb,foyzur/gpdb,cjcjameson/gpdb,kaknikhil/gpdb,adam8157/gpdb,tpostgres-projects/tPostgres,greenplum-db/gpdb,50wu/gpdb,zaksoup/gpdb,xuegang/gpdb,lisakowen/gpdb,lisakowen/gpdb,kaknikhil/gpdb,lpetrov-pivotal/gpdb,Quikling/gpdb,kaknikhil/gpdb,royc1/gpdb,adam8157/gpdb,lisakowen/gpdb,randomtask1155/gpdb,lisakowen/gpdb,ahachete/gpdb,techdragon/Postgres-XL,zaksoup/gpdb,50wu/gpdb,rvs/gpdb,adam8157/gpdb,arcivanov/postgres-xl,foyzur/gpdb,Postgres-XL/Postgres-XL,atris/gpdb,xinzweb/gpdb,lintzc/gpdb,CraigHarris/gpdb,yuanzhao/gpdb,jmcatamney/gpdb,ashwinstar/gpdb,rvs/gpdb,randomtask1155/gpdb,zaksoup/gpdb,Quikling/gpdb,snaga/postgres-xl,50wu/gpdb,ahachete/gpdb,atris/gpdb,0x0FFF/gpdb,zaksoup/gpdb,yazun/postgres-xl,yuanzhao/gpdb,Chibin/gpdb,postmind-net/postgres-xl,royc1/gpdb,adam8157/gpdb,kmjungersen/PostgresXL,pavanvd/postgres-xl,rubikloud/gpdb,jmcatamney/gpdb,techdragon/Postgres-XL,foyzur/gpdb,atris/gpdb,zeroae/postgres-xl,arcivanov/postgres-xl,pavanvd/postgres-xl,oberstet/postgres-xl,oberstet/postgres-xl,Quikling/gpdb,yazun/postgres-xl,lintzc/gpdb,cjcjameson/gpdb,janebeckman/gpdb,50wu/gpdb,Quikling/gpdb,atris/gpdb,edespino/gpdb,cjcjameson/gpdb,rvs/gpdb,zaksoup/gpdb,arcivanov/postgres-xl,lintzc/gpdb,janebeckman/gpdb,lpetrov-pivotal/gpdb,snaga/postgres-xl,ahachete/gpdb,ovr/postgres-xl,postmind-net/postgres-xl,zaksoup/gpdb,xuegang/gpdb,kmjungersen/PostgresXL