When generating reports from Google Analytics data, it is important to understand the collection and processing cycles of both Google Analytics and gShift as this can cause analytics totals to change up to 48 hours after the day in which the activity takes place on the site.
As you can see from the diagram above, there is a "post processing" cycle in Google Analytics which happens after the day is complete, and can provide slightly inaccurate values when collected in the early hours of the next morning. Approx 10% of the overall sites will experience this inconsistancy which will disappear after 48 hours. This inconsistance only happens for days which are within 48 hours of the current collection date.
If you are generating reports which contain GA data we recommend that you want for 48 hours AFTER your desired end period, to run the report