Which is the correct way to write the date in a business document?

There is no one correct way to write the date; many companies favour their own particular layout style. However, there are some basic conventions that should be followed.

Do not use a short form e.g. 6/12/06, as this indicates different dates in different countries. In American English it is 12 June but in British English it is 6 December.

Do not use short forms of the months e.g. Aug, Sept, as this looks unbusinesslike.

To avoid any confusion, it is best to write the date out in full using the following format: 6 December 2006 – this format also avoids the use of punctuation, i.e. December 6, 2006.

Remember we speak aloud “the 6th of December 2006” but we only write the actual day and month e.g. 6 December 2006.

Whichever model you choose, it is important to be consistent with its use.

Could you tell me whether I should spell numbers or use numerals?

Most style manuals agree with this simple rule: Spell all one-digit numbers (one to nine), and use numerals for any number having two or more digits.

There are some exceptions, but they’re logical and simple. Use numerals for all numbers in dates and street addresses, and for numbering consecutive items (such as paragraph numbers), no matter how high or low.

Also, use numerals for all numbers in a sentence if it contains both kinds (209 applicants for 5 jobs). The idea here is to be consistent within any sentence, to avoid confusing readers.

I’ve been told to write concisely using short sentences. How many words is a good average for a sentence?

You should try to say what you want to say in the fewest possible words but this doesn’t mean that you should always write in short sentences. Good writers will vary the length of their sentences to between 7 and 25 words. Sentences over 30 words should really be divided into two shorter ones. A good average length for a sentence would be about 19 words.