The first Halving Day was November 28, 2012, when block 210000 was generated.
How many more Halving Days will there be?
Bitcoin Stack Exchange is a question and answer site for Bitcoin crypto-currency enthusiasts. It only takes a minute to sign up.Sign up to join this community
The block subsidy will be reduced 33 times, 32 of them halving the block reward, and the last ("33rd halving") reducing it from 1 satoshi per block to zero satoshis per block.
You can find a table here (Google doc) that shows some metrics of the Bitcoin reward schedule including e.g. the number of halvings, their first blocks, and how much supply is left to be mined after each epoch.