get local time of every country

Question

hi
we r deveolping a website in which users from different countries visit the site.we want to get time of user's country. our server is lloacated in US and it give time of us when we use datetime.now() in code behind.
if we use javascript for client side execution, it will rertun the machine time which user is using. we want to get local county's standard time.
can anyone help me. it is too much, i searched a lot on google but no result...........