As absentminded as you may be, one holiday you’ll always remember is your birthday. On the other hand, the date of your conception is probably the one day you try desperately to forget.

Many believe these dates are completely random—a one in 365 chance for every person. But as it turns out, the day you were conceived is likely not as arbitrary as you think.

Using death record collections ranging from official government records to historic documents transcribed and digitized by various organizations, the genealogy experts at MooseRoots crunched the numbers to identify the most popular holidays to—ahem—start a family.

MooseRoots examined death records from 1936 to 2012 to identify birth dates of over 14 million people. They then subtracted 38 weeks (the average length of a pregnancy from conception to birth) to pinpoint the most likely conception date. Then, MooseRoots mapped dates for 14 holidays all the way back to 1936. In order to account for the varying lengths of pregnancy, they extended each "holiday" to include the week before and after.

Without further ado, here is the list of holidays babies are most likely to be conceived on.

#14. Labor Day

Total babies conceived around Labor Day in our data set: 551,197

Percent conceived around Labor Day: 3.70%

Percent conceived on Labor Day compared to average: -0.35%

#13. Independence Day

Total babies conceived around Independence Day in our data set: 569,054

Percent conceived around Independence Day: 3.82%

Percent conceived on Independence Day compared to average: -0.23%

#12. April Fool's Day

Total babies conceived around April Fool's Day in our data set: 583,169

Percent conceived around April Fool's Day: 3.91%

Percent conceived on April Fool's Day compared to average: -0.14%

#11. Easter

Total babies conceived around Easter in our data set: 586,142


Percent conceived around Easter: 3.93%


Percent conceived on Easter compared to average: -0.12%

#10. Cinco De Mayo

Total babies conceived around Cinco De Mayo in our data set: 588,979

Percent conceived around Cinco De Mayo: 3.95%

Percent conceived on Cinco De Mayo
compared to average: -0.10%

#9. Memorial Day

Total babies conceived around Memorial Day in our data set: 591,218

Percent conceived around Memorial Day: 3.97%

Percent conceived on Memorial Day
compared to average: -0.08%

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#8. Mardi Gras

Total babies conceived around Mardi Gras in our data set: 592,743

Percent conceived around Mardi Gras: 3.98%

Percent conceived on Mardi Gras
compared to average: -0.07%

#7. St. Patrick's Day

Total babies conceived around St. Patrick's Day in our data set: 592,937

Percent conceived around St. Patrick's Day: 3.98%

Percent conceived on St. Patrick's Day
compared to average: -0.07%

#6. Valentine's Day

Total babies conceived around Valentine's Day in our data set: 593,376

Percent conceived around Valentine's Day: 3.98%

Percent conceived on Valentine's Day
compared to average: -0.07%

#5. Presidents Day

Total babies conceived around Presidents Day in our data set: 596,002

Percent conceived around Presidents Day: 4.00%

Percent conceived on Presidents Day
compared to average: -0.05%

#4. Halloween

Total babies conceived around Halloween in our data set: 604,120

Percent conceived around Halloween: 4.05%

Percent conceived on Halloween compared to average: 0.00%

#3. Thanksgiving

Total babies conceived around Thanksgiving in our data set: 612,364

Percent conceived around Thanksgiving: 4.11%

Percent conceived on Thanksgiving compared to average: 0.06%

#2. New Year's Eve

Total babies conceived around New Year's Eve in our data set: 617,582

Percent conceived around New Year's Eve: 4.14%

Percent conceived on New Year's Eve
compared to average: 0.09%

#1. Christmas Day

Total babies conceived around Christmas in our data set: 617,900

Percent conceived around Christmas: 4.15%

Percent conceived on Christmas compared to average: 0.10%

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