To determine which range of dates gets shown and to calculate the number of days in your current streak. I guess could do the latter on the client, but what if

To determine which range of dates gets shown and to calculate the number of days in your current streak. I guess could do the latter on the client, but what if it's Aug 31st in CA and Sept 1st in MA and the user is in month view? I'm not yet ready to go all js.