The battery should only be taken out, when Daysy signals you to do so, in which case the battery should be changed according to instructions. However, if you took the battery out and did not immediately replace it and Daysy was left for a long time without any power, she has no way of tracking what day it is, even though the data is safe. Daysy’s internal calendar doesn’t synchronize with the calendar on daysyView.
When power is reapplied, Daysy still uses all the old cycle data, but waits for the first menstruation day to re-synchronize with your cycle.
For now, daysyView simply hides the old data because it’s not 100% sure on which calendar days it should display it. We understand this may be frustrating to you, and are working on a solution in a future version of daysyView.
There’s a simple work around though. Just don’t take the battery out of Daysy! We’ve done extensive testing and generally we haven’t found a strong reason ever to do this. The battery lasts for > 2 years (and Daysy warns you with enough time to spare about changing it) and the software in Daysy is very stable.
If you have trouble communicating with daysyView, the problem most likely lies with the mobile App. With each release of daysyView, we work to make this communication more stable, but on occasion something slips through. Please check out the daysyView FAQ items, and if you’re stuck, we’ll be happy to help you through e-mail or on the phone.