I need to sleep 8 hours a night/day

[AlexAD]

Hello.

In the sentence 'I need to sleep 8 hours a night/day' my book says that the night is correct. Is the day then incorrect? (By the day I mean the whole day from the beginning of the previous night to the end of the current night)

Thanks, Alex.

 

[bhaisahab]

Hello.

In the sentence 'I need to sleep 8 hours a night/day' my book says that the night is correct. Is the day then incorrect? (By the day I mean the whole day from the beginning of the previous night to the end of the current night)

Thanks, Alex.

'I need to sleep 8 hours a night' is more usual, but there is nothing wrong with using "day". Some people work at night and sleep during the day.

 

[Rover_KE]

Eight hours a day is commonly taken to mean a more-or-less continuous period of eight hours during each 24-hour day.

Eight hours sleep can be taken at any time - whether it's daylight outside or night-time.

Rover

 

[billmcd]

Hello.

In the sentence 'I need to sleep 8 hours a night/day' my book says that the night is correct. Is the day then incorrect? (By the day I mean the whole day from the beginning of the previous night to the end of the current night)

Thanks, Alex.

I understand what you mean, but if someone made that statement to me (i.e. using 'day'), they would have to include a more precise meaning. Even with your definition, it would not be clear to me whether your sleep occurs during the day, during the night or at intervals of sleep throughout a 24 hour period. Suggest you follow your book's rule/answer.

 

[AlexAD]

I understand what you mean, but if someone made that statement to me (i.e. using 'day'), they would have to include a more precise meaning. Even with your definition, it would not be clear to me whether your sleep occurs during the day, during the night or at intervals of sleep throughout a 24 hour period. Suggest you follow your book's rule/answer.

Thanks, billcmd, for your thorough reply.

Now I understand that there is some difference in Russian's equivalent.

Thanks, Alex.

 

[BobK]

I understand what you mean, but if someone made that statement to me (i.e. using 'day'), they would have to include a more precise meaning. Even with your definition, it would not be clear to me whether your sleep occurs during the day, during the night or at intervals of sleep throughout a 24 hour period. Suggest you follow your book's rule/answer.

.... Or just use the colloquial 'I need my eight hours'. the [sleep] is understood.

b

 

[Raymott]

Hello.

In the sentence 'I need to sleep 8 hours a night/day' my book says that the night is correct. Is the day then incorrect? (By the day I mean the whole day from the beginning of the previous night to the end of the current night)

Thanks, Alex.

"the night" is wrong.
"a night" and "a day" are correct.
If you say, "I only sleep 2 hours a day" (but you sleep 6 hours each night), then you are being perverse, and not communicating in good faith.
The same applies if you say, without explaining, "I only sleep 2 hours every night" (if you sleep for 6 hours during the day).
If you want to specify that you are talking about "during the day" or "at night", etc. then you should use those terms, not "a day" or "a night".