it is common for applications to be approved "out of order".
a) the applications are batched by months, not necessarily by day.
b) an officer probably isn't going to receive applications on their desk that represent every single day in a said month, since the work load is split amongst more than 1 officer.
c)each officer has their own level of ability to process applications in a certain amount of time. certainly there will be differences in the length it takes different officers to finish their work.
d) just because the website says it's processing applications for a certain date, it certainly doesn't mean ALL applications received before that date are finished processing or even open.
e) each application is unique. how quickly it takes cic to process an application depends on the information provided and how easily and quickly cic can confirm the information provided.