adjacency

1. The state of being adjacent; contiguity.
2. A thing that is adjacent.

Broadcast: scheduled radio or television program immediately preceding or following another scheduled program on a particular station.

Broadcast advertising: time period (usually two minutes) that precedes or follows network programs; also called commercial break position. It is offered for sale for local or spot advertisers. commercial time is sold on the basis of the ratings of adjacencies: the higher the rating, the greater the listening or viewing audience, and therefore the greater the cost of the time period. The audience potential of an adjacency is greater than that of a program commercial position because of the fact that many people keep their television or radio tuned in to the following program after hearing or viewing the preceding adjacency. Similarly, many who want to see or hear a program will tune in early and are thus exposed to the commercials in the break position.

The noun has one meaning:

Meaning #1: the attribute of being so near as to be touching
  Synonyms: contiguity, contiguousness