Following a decision by the Government, transmitters are being updated region by region as part of a major engineering programme being carried out between now and 2020.
The required changes will take place on the following dates at transmitters in the areas listed below:
Engineering work at main transmitters will begin shortly after midnight on each day and some Freeview channels will be off-air overnight until 6am.
After this, any viewers receiving their TV signal from these who find they are missing channels can retune.
Services from smaller local relays may be subject to disruption until late afternoon.
Satellite and cable TV are not affected.
The following retuning dates take place across Yorkshire:
Wednesday October 23 - Lincolnshire and east Yorkshire served by the Belmont transmitter; most of Yorkshire served by Emley Moor; Sheffield; and some of the Idle area.
Wednesday November 13 - Some of the Idle area; Central and north east Keighley served by the Keighley Town transmitter group, the Scarborough area service by Oliver's Mount; and parts of west Bradford.
Around 2.5m homes are served by the affected transmitters.
Freeview will be running an information campaign to prepare people for the change, including advertising and on-screen messages.
Further required changes will take place at some transmitters in 2020, following the completion of engineering work in neighbouring areas.
Retuning should be straightforward and some TV equipment will retune automatically.
Some older aerials may need to be replaced to continue receiving all channels.
Viewers may be eligible for free in-home support, including aerial work if needed.
Anyone who needs advice, or who finds they are still missing services after retuning, can visit the Freeview website at www.freeview.co.uk/tvchanges or contact the Freeview Advice Line free on 0808 100 0288.