1. Tap "BBT" at the top of the "Charts" page.
2. Tap the "+ Add reading" button on the "BBT Table" page.
3. Choose the desired date by setting "MM DD, YYYY" and tap on "__.__" to log your BBT, then save.
Note: In this way, the time of the temperature is the time you recorded and you can't set the specific temping time, only the date.