When creating a Live Goal, you set if you'd like to be prompted for updates weekly, bi-weekly, or monthly.

The schedule will automatically use the "Start Date" to determine when those updates are prompted. For example, the first weekly update will be asked 7 days after the start date.

If you'd like to coordinate Live Goal updates to fall on a specific day of the week, just backdate the "Start Date". For example, if you want updates on Thursdays, make the "Start Date" a Thursday.