first you don't need to put them together, you just need to track the line you want and take them from the second matrix (for example in unique you have index; if you use a logic low you can use find) but i think it better to add them together.
you can take all the date (y,m,d,...) and turn it to matlab date by using the function datenum. after this you can use datenum for your range (datenum('2014/12','yyyy/mm'), for example). for example, today (December 4) is 735937. so if you take all line between 735937 to 735938 you will get all data from (December 4).
I don't think unique can help you, i think find is the way to do this. it will find only the line you want and then you can do on this line any "manipulation" you want.
