Brunswick, like the other big labels, gave advance information about its releases to the Talking Machine World magazine. This record here, for instance, was announced in the February 15 issue, probably printed some days earlier, with copy deadline in late January. Thus I assumed that the records were generally released in the publication month of the magazine, although e.g. this February issue says "Advance Record Bulletins for March".
For later years, Victor and OKeh confirmed this assumption with exact release dates of the current month. In 1928, TMW changed the report headline to "The Latest Record Bulletins".
For Brunswick, I can't say for sure if the label always released its records in the magazine's publication month (it doesn't seem so), but the rather old sticker on this record says "Feb. 23" anyway, according to my assumption.