Should I provide you with the exact date of arrival?
No, not necessarily. The arrival date you provide should be the earliest you plan to arrive, but you can arrive after that date. The departure date is the last day you are permitted to be in the country, unless you get a visa extension.
For example: If you apply for a 1-month visa and submit your arrival date as Jan 1, 2011, the visa letter will be valid from Jan 1, 2011 – Feb 1, 2011. You can arrive anytime between Jan 1 – Feb 1 but must leave the country by Feb 1, 2011.”