Export Service Date of Booking

i have done it for export of goods
exchange rate used is RBI reference rate
up to 10 July you will get on RBI site and then 10 July onward FBIL website
with regard to date we have taken LEO date as base (need to analyse control test- case based)

means we need to refer RBI reference rate to book invoice, but I didn't understand LEO date, kindly explain

Only rates given by CBEC are relevant. 

I think cbec rate is not relevant for account books. yes I admit most of people are using cbec rate but this is wrong
it can be also be clarified from one of publication of IDT committee of ICAI on gst audit report
https://idtc.icai.org/publications_record.php?code=aHR0cHM6Ly9pZHRjLWljYWkuczMtYXAtc291dGhlYXN0LTEuYW1hem9uYXdzLmNvbS9kb3dubG9hZC9wZGYxOS9UZWNobmljYWxfR3VpZGVfb25fR1NUX0F1ZGl0LTQtNi0xOS5wZGY=&pub=Technical%20Guide%20on%20GST%20Audit

pg 75 S. No. 5N eg is also given

practically what we are doing is to make invoice when material is out of factory at cbec rate because e way is also to be made and for balance sheet at year end one adjustment entry is passed to change sales and forex gain/loss