A big problem for me to synchronizate the data in excel

there are 6 groups of data,each including a datw col and an 'equity' col,

the beginning date,ending date,and the date in this period are not the same

I wanna to match the equity data by the date (that's,make the date synchronizated)and sum them up each line
(the result of a blank line = the result before it)

for example,there are 2 groups of date

1996-9-2 48550
1996-9-3 49150
1996-9-4 48750
1996-9-5 48650
1996-9-6 52350
1996-9-9 52100
1996-9-10 51550


and

1996-8-30 49800
1996-9-2 49150
1996-9-3 49400
1996-9-9 50350
1996-9-10 50300
1996-9-11 51050
1996-9-12 51650

so I wanna to make the combined data as:

1996-8-30 49800
1996-9-2 49150 48550
1996-9-3 49400 49150
1996-9-4 49400 48750
1996-9-5 49400 48650
1996-9-6 49400 52350
1996-9-9 50350 52100
1996-9-10 50300 51550
1996-9-11 51050 51550
1996-9-12 51650 51550
...
Could anyone here help to make it into reality,please?
Thanks in advance!