There are [2 589 420 Facebook users in the Singapore][1]. They each spend 38 mins and 46 secs on Facebook per day making Singapore #1 in terms of time spent per user (Can't reference this off-hand).
United States has [155 701 780 users][2]. All the Facebook users from the US spend a total of [100,000 years on Facebook each month][3]. American users spend an average of 6 hours and 33 minutes on the social network each month.
Normalize:
38 mins and 46 secs user/day = 2326 seconds on Facebook user/day
Total for singapore: