Combining multiple columns of data into single column

Hello,

I was wondering if anyone knows how to combine multiple columns of data into one sorted column. I would like the sorted column to be in chronological order and the respective data to stay with its corresponding date. Also, I should note that these columns will be growing on a daily basis...not sure if that will matter or not. I've attached a simplified example.

One other question. If my data in columns A through D are being drawn from another sheet via the Index and match functions, will that affect the ability to make one sorted column?

Thanks,

Dan