Programming Help

AMPS-N:
can some tell me how did we assigned this address:#define DS1307_I2C_ADDRESS 0x68 . how we get this I2c address

This is a cross-post of this, right?

AMPS-N:
can some tell me how did we assigned this address:#define DS1307_I2C_ADDRESS 0x68 . how we get this I2c address