Queries :: Importing Data From Clocking On System To Analyse Worked Hours - Link Paired Record?

I have been tasked with importing data from a clocking on system to analyse worked hours.

There is no option to amend the format of the export which is not great

surnameforenameField2Field3xxx
xxx
11/06/201319.18
xxx
xxx
11/06/20135.37+
xxx
xxx
12/06/20135.41+
xxx
xxx
12/06/201319.21

The plus indicates a night shift worker
eg started at 19.18 and finished at 5.37 on the 12th

so for every record I have staff id , date, and clock time ( I have stripped out the + ) and created a yes/no field to identify the records where field2 should actually be field2+1

I have sat in query design screen for ages and cant think how on earth I am going to calculate hours worked for a given staff member and date combination.

for every combination of staff id and date there should be 2 records - a clock in and a clock out

I thought about creating new fields clockin and clockout but struggling to see how I can link the 2 "paired" records together

vb script with dlookup for every record ?