Does Daylight Saving Time Affect Your BBT? Science Answers


I have a love/hate relationship with daylight saving time ending. On the one hand, who doesn't want an extra hour of sleep and lighter mornings? I'm a morning person; I wake before the sun on most days. But, on the other hand, it means my kids' schedules are screwed for a week and it gets dark before brunch is done being served for the day. Does it screw up anything else? Like when you take your birth control? What about trying to conceive? Does daylight saving time affect your BBT?

The basal body temperature is your body's temperature at absolute rest. During your menstrual cycle, it will go through a series of dips and spikes that indicate the production of the hormone that triggers the release of the egg from the ovary, resulting in ovulation and the fertile period of your menstrual cycle, according to the American College of Obstetricians and Gynecologists. While it is sensitive to many exterior factors like illness and ambient temperature, as well as time change, it's more dependent on your sleep/wake cycle, noted the Mayo Clinic. Therefore, if you're taking your temperature immediately upon rising as opposed to a specific time each day, your basal body temperature shouldn't be significantly impacted by the switch away from daylight saving time.

Daylight saving time (DST) began as a way to make better use of the daylight hours that spread from the spring to the early fall. The more daylight the day had access to, the better for farmers and their ilk to be able to easily perform their duties, according to There is now some real debate happening in congress and amongst social scientists as to whether or not this system of setting the clocks either backwards or forwards depending on the season is now antiquated, and possibly serves as more an agent of annoyance than predictor of agricultural success since we've moved away from our traditional agrarian roots.

For parents, DST represents days or possibly weeks of interrupted sleep and crabby children. In the spring, they're pissed off you have the audacity to force them to rise before their little body says it's time, and in the fall, they wake up before you've even had your coffee. It's a misery for parents on par with forced bake sales and playground mothers. To think that it could be problematic before you even get the chance to become pregnant seems especially insulting if you ask me.

Tracking your BBT is as second nature to women who are TTC as is taking your prenatal and saying things that begin with "when I have a kid, I'll never..." However, most women do their best to take it at the same time every day, and DST is an interruption in the flow on their chart. Fortunately, DST shouldn't be a big deal if you're tracking your BBT properly. According to The Mayo Clinic, when you measure your BBT isn't incumbent upon a specific number on a clock each day, but instead, it's reliant upon when your eyes first open in the morning. It's instructed on their website to measure your BBT as soon as you wake up in the morning. You should do it with the same instrument every day, and it should be done before your coffee, before your water, and even before you speak.

So whether you're rising at the crack of dawn or some time during Good Morning America, as long as you're taking that temperature in the same place with the same thermometer every day, you should be getting an accurate reading regardless of if you've managed to steal a few more winks.

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