Incorrect-dates-for-periodic-returns-data-Resolved

Data from the periodic returns data gives wrong dates:

CODE:
Weekly   %Return
12/30/1899   0
12/31/1899   1.254941325000007
1/1/1900   3.094910563368521
1/2/1900   1.606510849711632
1/3/1900   -3.4150094149869927
1/4/1900   1.2590613562717385
1/5/1900   0
1/6/1900   0
1/7/1900   0.09291996929918009
1/8/1900   0.1164312758720258
1/9/1900   1.8886548644397205
1/10/1900   -0.1967635442834765
1/11/1900   0.08378937326103403
1/12/1900   0
1/13/1900   -2.4178483312699175
1/14/1900   1.811544074235435
1/15/1900   1.8199014192831098
1/16/1900   1.7386170260966518
1/17/1900   0.014292548666326349
1/18/1900   2.255858476943577
1/19/1900   0
1/20/1900   0

I try to find a way to check the last few days (e.g. a week) daily returns after I run my metastrategy each day. Is there an easier way to check this?