Hey Sam, sorry for the confusion! I think I already replied to your email on this, but thought I would copy over the reply here, in case other Newbees have the same question!
Beeminder always calculates a daily rate, partly because it’s a straight line graph that has days as the unit on the x-axis, and partly because it’s appropriate for most goals to want to make consistent progress over time instead of bunching up at the end of a week. So what happened in this case, is that your goal converted your weekly rate into a daily rate of 0.571/day (4/7), and since the goal rounds up in cases like this, it is asking you to complete 1 of your 4 weekly habitica todos by the end of the day. Does that make sense?
Depending on your goal, though, you’ll probably find that setting it up with a week of safety buffer to begin is a good workaround. In that case, your goal only starts to become due at the end of the week, and once you’ve entered your data, it won’t be due for another week, etc. (This thread on the forum might help you visualise that!)