Fill in Missing End Dates in Table

I have a table where ever once in a while there is missing data on one of the date fields that calculates the production time of an item. Basically, I have a start date but sometimes I don't get an end date even though the product has gone on to the next line. 

So, what I'm trying to do is write a fomula that will give me the "Adjusted End Date" column shown in the table below. I have a column called "Order" that also shows the process order,  but cannot figure out how to pull the Start date from another row based on the next step in that order column. 

Note, I need to use that order column as the sequential order as sometimes a product goes through two lines on the same day so I need to reference the production order. 

Thanks!