A method and an apparatus for transmitting broadcast signals thereof are disclosed. The apparatus for transmitting broadcast signals, the apparatus comprises an encoder to encode service data, a mapper to map the encoded service data, a time interleaver to time interleave the mapped service data, wherein the time interleaving is performed depending on number of physical paths for the service data, a frame builder to build at least one signal frame including the time interleaved service data, a modulator to modulate data in the built at least one signal frame by an OFDM (Orthogonal Frequency Division Multiplex) scheme and a transmitter to transmit the broadcast signals having the modulated data.