Clarification of　半日　in this sentence


> 一度足を踏み入れたが最後、 **むこう半日は** 鏡面恐怖症におちいる大迷路のなれの果てが、こうして草十郎の目の前に立ちふさがっているのだが.

The protagonist is going into a building where there is a mirror house and
another attraction. The building is now abandoned and he is going to another
place different from the mirror house to meet someone else.  
It's night and there are no lights.

> Once he stepped in, on the other side there is the mirror-phobic big
> labyrinth which is nothing but a shadow of it's former self which is now
> standing in front of Souichiro but.

I don't understand that half a day in there.  
Since it's night and the building has been abandoned I think it's because half
a day there is no sunlight so it' all dark and so it serve no purpose, but I
am just guessing.

Can someone clarify?




Came for dead rubber.

* * *

The dictionary says:

> **[むこう〔むかふ〕【向こう】](http://dictionary.goo.ne.jp/jn/214932/meaning/m0u/)**
>
> **４** 今後。これから先。「―三日間」

But I'd rather say it's virtually an adjective in this meaning, for it's
always followed by phrase represents time duration.

> 向こう半日 _(for) the next half day_
>
> 向こう一週間の天気 _weather for the next seven days_




Came for dead rubber.

* * *

The dictionary says:

> **[むこう〔むかふ〕【向こう】](http://dictionary.goo.ne.jp/jn/214932/meaning/m0u/)**
>
> **４** 今後。これから先。「―三日間」

But I'd rather say it's virtually an adjective in this meaning, for it's
always followed by phrase represents time duration.

> 向こう半日 _(for) the next half day_
>
> 向こう一週間の天気 _weather for the next seven days_

