Daylight Saving Time and Your Birth Control Pill

Daylight Saving Time and Birth Control
Daylight Saving Time and Birth Control Pill?. Anthony Harvie/Getty Images

What is Daylight Saving Time?

Since World War I, Daylight Saving Time has been used in the United States and in many European countries. During Daylight Saving Time, we advance our clocks during the spring/summer months by one hour. This allows daylight to last an hour longer. Places that follow Daylight Saving Time will move their clocks forward one hour near the start of spring and adjust them back to standard time in autumn.

We often use the terms "spring forward" and "fall back" when referring to this.

Daylight Saving Time: A Brief History:

Daylight Saving Time was not formally adopted in the US until 1918—on March 19, 1918, an official bill was created with the intent to preserve daylight and provide standard time for the United States. After World War I ended, the bill was not very popular, and President Wilson ended the bill—but allowed each state to decide whether or not to observe Daylight Saving Time (and when it started and ended). This created a lot of confusion! So, in order to create one pattern across the country, President Lyndon Johnson signed the the Uniform Time Act of 1966 into law on April 12, 1966. This law established a uniform period to observe Daylight Saving Time while also allowing any state ti be exempt from the Uniform Time Act by passing a state law.

When Do We Observe Daylight Saving Time?

Most of the US begins Daylight Saving Time at 2:00 am on the second Sunday in March and goes back to standard time on the first Sunday in November.

In the spring, clocks "spring forward" from 1:59 am to 3:00 am—in the fall, clocks "fall back" from 1:59 am to 1:00 am. Each time zone in the US switches at a different time.The following states and US territories do NOT observe Daylight Saving Time:

  • Arizona
  • Hawaii
  • American Samoa
  • Guam
  • Puerto Rico
  • The Virgin Islands
  • The Commonwealth of Northern Mariana Islands

The beginning and ending of Daylight Saving Time can sometimes be confusing and may cause problems when traveling, with sleep, and/or with taking medication (like the Pill).

Daylight Saving Time and Your Birth Control Pill:

It is very important to remember that you will have maximum pregnancy protection as long as you take your birth control pill at about the same time every day (this is true for both progestin-only pills and combo pills). Why? Well, when you take the Pill at the same time each day, it allows there to be enough hormone (estrogen and/or progestin) in your system to keep you from ovulating. If you forget to take a pill or take one at a later or earlier time, the Pill could become less effective—this is because there may not be enough hormones in your body. So, when it comes to Daylight Saving Time, don't forget about your pill!

When Daylight Saving Time Starts:

When Daylight Saving Time goes into effect, make sure to "spring forward" and set your clocks one hour ahead.

In anticipation for the time change, Julianna emailed me a question about Daylight Saving Time and her birth control pill. So, if you are wondering the same thing, here is Julianna's question:

I take my birth control pill (Yaz) at 10:00 PM every day. When we have to set the clock ahead an hour for Daylight Saving Time, what should I do? Do I take it at 11:00 PM (the time that WOULD have been 10:00 PM)? Or can I continue to take it at my normal time?

Most medical professionals agree that there is about a 1 to 2 hour window period where the effectiveness of your birth control pill is not compromised. This means that if you take your pill anywhere from an hour earlier than you normally do until an hour later than your regular pill time, the Pill should still work just fine. So, when Daylight Saving Time begins, you could still take your pill at the same time that you normally would—so, in Julianna's case, that would be 10 PM.

If you take your Pill at your regular time, your body will only feel as though you're one hour early with your hormone dose. Since there is medical agreement that taking the Pill one hour earlier than usual is fine, it is okay to just continue taking your pill at your normal time (and not adjust for Daylight Saving Time).

If you would rather be super-cautious, then it may be better to adjust your pill-taking time. This means, at the beginning of Daylight Saving Time, switch the time you take your pill to what WOULD have been your usual time. So, in Julianna's case, she should start to take her Yaz pill at the adjusted time of 11:00 PM instead of 10:00 PM.

Really want to keep your "usual" time? After your placebo week is over and you begin a new pack of pills, you can go back to taking them at your "normal" time—such as 10 PM (as in Julianna's question).

What About When Daylight Saving Time is Over?

Now, let's consider Lexi's question...

I take my Ortho Tri-Cylcen Lo pill at 9:00 AM each day. Since Daylight Saving Time is going to be over, and we need to set the clock back an hour, should I start to take my pill at 8:00 PM?

Technically, the Pill only protects against pregnancy for a 24-hour period—BUT, there is about an hour or two of "wiggle room." So, when Daylight Saving Time is over (and the clock is moved back one hour), it may be wise and just adjust your pill use. Take your pill one hour earlier than you normally would. You can always go back to taking the Pill at your “regular” time when you begin your next pack of pills (after the placebo week is over).

The Bottom Line:

Although taking your pill an hour earlier or later generally does not matter, taking your pill one hour earlier (as opposed to one hour later than usual), is a slightly better option. Also, when it comes to Daylight Saving Time, keep in mind that computer software programs and smart phones will USUALLY—but not ALWAYS—automatically update the time. If you rely on a reminder email/text, your phone's alarm, or a birth control app to remind you to take your pill, make sure that your devices have adjusted the time for the start or end of Daylight Saving Time.

When it comes to Daylight Saving Time, there is really no reason to become overly anxious about adjusting when you take your pil. As long as you are still taking your pill within an hour of when you normally do, put your worries away! The most important point to remember is that you will have maximum protection as long as you take the pill at about the same time every day.

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