my wife submitted her family visa application on the 12th jan 2010. today we have recieved confirmation that it has been processed and return by courier. i hope its good news, its taken just over 2 weeks. on the application i put that she hopes to travel on march 29th and return around july 29th. would it matter if i change the dates but keep within the dates that the visa is issued. these dates were only a rough guide. she will not stay longer than 4 months as we have children in the philippines. also is there a period of time that she must travel before the visa is invalidated i read somewhere it must be used within 28 days of issue?