I represent the W/P Electronics Company in Dallas, and will be in Kunming from next Monday to Friday, (October 5-9). I should like to call on you to discuss our new monitor. Would 0930 hours on Tuesday, October 6 be convenient?
I shall be in Beijing, at the Great Wall Hotel, from Tuesday, September 29, until Sunday, October 4, where a message will reach me. If the day is not convenient, will you please suggest another.
Please accept my apologies for the delay in acknowledging your invitation for [lunch/ dinner/ cocktails] on [September the fourth, this year]. I have been away form the office and only just returned.
Unfortunately, I have other plans for the date you mention, but shall be happy to make a date for some other convenient time.