How do we say "day" in Japanese ?
こんにちは！(^o^)/
Actually, I'd like to know what is the Japanese word for "day".
I've searched it on the internet but it says that it depends on the context. Well, my sentence is "today was a tiring day".

Can someone help me please ?
Thank you in advance. :)

Question

How do we say "day" in Japanese ?
こんにちは！(^o^)/ 
Actually, I'd like to know what is the Japanese word for "day". 
I've searched it on the internet but it says that it depends on the context. Well, my sentence is "today was a tiring day".

Can someone help me please ? 
Thank you in advance. :)

Answer

Yes. It does depend on the context. In this case I'd say: 
今日は忙しい一日でした。（きょうはいそがしいいちにちでした。） 
Also I think ひ（日）could be used. Like Blaine said before.

Answer

To say today you would say 今日(きょう)。
So your sentence would be "今日は忙しい日でした。(きょうはいそがしいひでした)

Answer

Yes. It does depend on the context. In this case I'd say:
今日は忙しい一日でした。（きょうはいそがしいいちにちでした。）
Also I think ひ（日）could be used. Like Blaine said before.