Relative Time Kanji?

[Ertai87]

OK, so I'm learning Kanji in my Japanese class this term, but I have a question about it. We've learned the kanji 先 and 来 for "previous" and "next", as in words like 先週 (last week) and 来月 (next month), but my question is: Can you say things like 来晩 for "tomorrow night" or 先朝 for "yesterday morning"? It makes it much easier than using 昨日 and 明日 all the time if this is allowed...

Also, on a slightly different topic, for the kanji I have to learn this week, I have to learn both 夜 and 晩...what's the difference? They seem interchangeable in almost every circumstance...

[Vagrere]

For your first question: No, you don't use 先 or 来 to refer to times that will occur/have occurred tomorrow or yesterday, but there is a simpler way: since the characters 明 and 昨 are really the only ones we're interested in the compounds 明日 and 昨日, it's understood if you just drop the 日 when referring to times during those days. In other words, 昨朝 is yesterday morning, and 明夜 is tomorrow night. You can extend this to some other common ideas concerning "yesterday" and "tomorrow": tomorrow evening would be 明晩, or perhaps 明夕; yesterday, in the (particularly) early morning is 昨暁.

As to your second question, so far as I'm aware, there's not much difference; generally, it's just a question of what sounds better where.

[Ertai87]

Cool, thanks. How are those pronounced though?

[Vagrere]

In compounds, 昨 is generally pronounced "saku," and 明, when referring to tomorrow, is generally pronounced "myou." The compounds I have here are:

(昨朝) sakuchou
(明夜) myouya
(明晩) myouban
(昨暁) sakugyou

明夕 isn't a compound I could find in my dictionary, and a google search only turns up upwards of 70,000 pages for it, but that would make me think it's probably just rare/poetic/both. My guess is that it should be pronounced either as "myouyuu" or "meiyuu," but I couldn't tell you for sure. The compound 昨夕 is more common, however, and is pronounced "sakuyuu."