Your fertile days, identified clearly

Yellow is normal - especially early on. It means Daysy is still building your personal pattern and isn't ready to classify the day with certainty. Most women see more yellow in their first one to three cycles, with green days increasing as the algorithm learns their rhythm. Yellow isn't a problem. It's Daysy being careful before it commits.

Yes. Daysy reads your morning temperature each day rather than predicting from cycle averages, so cycle variation doesn't break it the way it breaks apps. It supports cycles between 19 and 40 days, including women with PCOS whose cycles fall in that range. Expect more yellow days in your first one to three cycles while Daysy learns your rhythm — that's normal. If your cycles are consistently longer than 40 days, we recommend speaking with a clinician before purchasing — Daysy isn't a replacement for medical investigation.

Most users see green days within their first cycle. The number grows as Daysy learns your pattern - by cycle two or three, most women have a clear, consistent picture of their fertile and non-fertile days. The first cycle has more yellow days than later ones, and that's expected. Daysy is building your personal baseline from scratch. Give it the full cycle and it will give you the clarity you're paying for.

Not yet — but the timing is closer than most women expect. Prolactin, the hormone that supports milk production, suppresses ovulation and affects basal body temperature, which means the signals Daysy relies on aren't reliable during this period. Most women start using Daysy once their first postpartum cycle returns, typically around six weeks after breastfeeding ends. If you're unsure about timing, your GP or midwife can advise.

Yes. Missing an occasional reading won't erase your progress — Daysy recognises patterns over time, not through perfect daily input. Daysy needs at least three hours of uninterrupted sleep before your morning reading, so on nights that weren't settled — shift changes, jet lag, illness, or a rough night — skip the reading. Consistent readings on settled mornings are what build your cycle picture. Daysy is designed for real life, not laboratory conditions.

Yes. The DaysyDay app is included at no additional cost and has no subscription fee. Your S$449 covers the device and lifetime app access on iOS and Android.

It means the accuracy figure has been tested in published research, not just claimed. A peer-reviewed study followed 5,328 users across approximately 107,000 cycles — published in the European Journal of Contraception & Reproductive Health Care (van de Roemer et al., 2021). Daysy's algorithm has been evaluated across 17 clinical studies in total. Clinically validated means there is a body of evidence, not a marketing line.

No. Daysy isn't registered or sold as a contraceptive device and isn't designed to prevent pregnancy. Its purpose is to help you understand your cycle by identifying temperature-based patterns. If you need contraception, use a method tested and approved for that purpose.

No. Daysy doesn't diagnose medical conditions or confirm hormone levels. What Daysy does is identify temperature-based patterns across your cycle — it tells you where you are in your cycle, but it can't tell you why. If something in your pattern looks unusual, it's worth bringing to a clinician.

Your data stays private and under your control. Stored on your device, syncs securely, never shared or sold. Your body is your business.