I have made phone call.

It is important to remember that the basis for the current online index actually goes back to the volunteer work done in the 1930s.

It is also important to remember that entries prior to WWI are based on verbal information, particularly for births.

While the clerk at Albury Court House would be familiar with registering births, the parent will not be as knowledgeable.

The registrations were MEANT to be sent through to Sydney each quarter, so Oct, Nov, Dec were sent through in January. (Jan/Feb/March in April etc) (Some were sent annually, others were not sent at all.... and were NOT actually formally found until the 1980s when all court house registers were recalled to Sydney)

However, when the volunteers in the 1930s were preparing the indexes, some volunteers only wrote down the year of birth, and so the current index for these ones allows for ANY date in that YEAR ....

Back in the 1970s NSW BDM went EDP and the date of birth and year of registration were both keyed in. NOT all the cards 'worked' .... some were jammed in the process, some fell, some tore, some had flaws in the actual card ..... Sometimes only the year (four digits) were read.

When the 1930s index was brought across for the EDP processing, some entries were lost/destroyed/partly destroyed.

It is a miracle that any info survived, as there has always been a funding issue.

If you find a date of birth coming up for the ECRs then that's because back in the 1930s those volunteers found it on the originals they were indexing. But it is often more reliable at present to check the familysearch historic records index transcriptions to obtain the exact dates.
Sorry for diverting off the OPs topic with these explanations.
Cheers, JM