为什么这个where子句没有返回正确的记录？ - Rails 3

=> #<Gig id: 59, date: "2012-06-01 00:00:00", title: "Awesome Record", url: "https://someurl.com", body: nil, reply_email: nil, industry_id: nil, created_at: "2012-06-03 03:06:45", updated_at: "2012-06-03 03:06:45"> 


1.9.2-p0 :046 > Gig.where(:date => "2012-06-01 00:00:00")
  Gig Load (0.3ms)  SELECT "gigs".* FROM "gigs" WHERE "gigs"."date" = '2012-06-01 00:00:00'
 => [] 
1.9.2-p0 :043 > Gig.where(:date => "2012-06-01")
  Gig Load (0.3ms)  SELECT "gigs".* FROM "gigs" WHERE "gigs"."date" = '2012-06-01'
 => [] 
1.9.2-p0 :044 > Gig.where(:date => "June 01")
  Gig Load (0.6ms)  SELECT "gigs".* FROM "gigs" WHERE "gigs"."date" = 'June 01'
 => [] 
1.9.2-p0 :045 > Gig.where(:date => "June 1")
  Gig Load (32.9ms)  SELECT "gigs".* FROM "gigs" WHERE "gigs"."date" = 'June 1'
 => [] 
=> #<Gig id: 59, date: "2012-06-01 00:00:00", t