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Notes About Dates

Birth Dates

There are a number of different sources from which a person's birth date can be identified, including birth certificates, baptism records where a birth date is shown, military and maritime records, death certificates issued from the June quarter of 1969 onwards, the 1939 Register, family bibles and word-of-mouth. However none of these are necessarily reliable for various reasons.


Civil birth registration was introduced in England and Wales in September 1837 but initially it was the responsibility of the registrar rather than the parents to record births, leading to mistakes being made and some births being overlooked completely. From January 1875 under the Registration of Births and Deaths Act it became compulsory for parents to register births within six weeks and failure to do this could result in a fine. If parents failed to register a birth within this time limit they might invent a birth date that fell less than six weeks before the registration date in order to avoid being fined. Therefore if you find an alternative birth date which is just a few days prior to the one shown on the person's birth certificate, this could be the explanation.


Birth dates recorded on military and maritime records also need to be treated with caution as an individual might have claimed to be older than they actually were in order to join a particular service, while birth dates shown on death certificates would have been provided by an informant who might not have known the deceased's actual date of birth.

Birth dates shown in the 1939 Register were copied by an enumerator from a form completed by each household which could have resulted in transcription errors. It is also possible that the head of the household made a mistake when completing the form or may not have known the correct birth date for every occupant, and they may even have deliberately given false information to avoid conscription or to hide an embarrassing skeleton in the cupboard, such as a large age gap between spouses or illegitimacy of a child. Also, if someone had previously lied about their age in order to join a military or maritime service they may have felt obliged to do so again when completing the 1939 registration form.


Birth dates recorded in baptism registers are likely to be more reliable as there is no obvious reason why a false date would be provided, though hiding illegitimacy could again be a possibility, however they still need to be treated with caution as clerical errors sometimes occurred, and it was also claimed that parish records were sometimes deliberately altered or erased. While one would imagine that family bibles are a reliable source it's worth bearing in mind that the owner of the bible may not have had correct information about when more distant relatives were born, or may simply have made a mistake when recording someone's birth date.


Even word-of-mouth is not guaranteed to be correct as some people did not know exactly when they were born – just because they celebrated their birth on the same day every year does not necessarily mean that this was the date they were actually born!


So if you only have a single source for someone's birth date you cannot be sure that this is correct. If however you have two or more corroborating sources then you can be more certain that the date is right. If on the other hand you have birth dates from a variety of sources and none of them agree then you simply have to record all of them and in your family tree show that the person was born 'circa', 'after' or 'between' a particular date or dates.

On my website I list all the known children born to the same parents and it would be confusing and untidy to show multiple birth dates for them. I have therefore decided to show just one birth date. Prior to 1837 (when civil registration was introduced) most birth dates shown on my site will be from baptism registers, though some might come from gravestones and a few have been deduced from military and maritime records. After 1837 where I have a person's birth certificate I will show the date recorded on it, unless I have a good reason to show an alternative date (e.g. where several other  sources agree that the person was born on a different date). For individuals where I do not have a birth certificate, birth dates will have been primarily taken from the 1939 Register and death records. In a few cases dates have come from family bibles and more recent birth dates may have been provided by family members with whom I've corresponded.

It is therefore important to be aware when reading the pages of my website that I cannot guarantee that the birth dates I have shown are correct. This of course is also true for other dates – marriages, deaths, baptisms, burials, etc. – though there are fewer reasons why these could have been incorrectly recorded in official documents. If you are related to anyone in my family tree from whom I've provided a birth date, I would recommend that you attempt to corroborate that date yourself before simply copying it into your own family tree.

If you have any reason to believe that any dates recorded in my website are incorrect, please do get in touch and if I concur that an alternative date is more likely to be right I will happily update my information.

Double Dates

In 45BC Julius Caesar introduced a new calendar with 365 days in a "normal" year and 366 in every fourth year or "leap year". This calendar became known as the Julian calendar. However, the Julian calendar was 11 minutes and 14 seconds longer than the solar year, a discrepancy which accumulated over time until by 1582 the vernal equinox occurred 10 days early and church holidays did not occur in the appropriate seasons. In order to make the vernal equinox occur on or around 21st March, Pope Gregory XIII decreed that ten days should be dropped from the calendar. In order to prevent the discrepancy from reoccurring the Pope introduced a new calendar in which leap years still occur every fourth year except where it is a century year (i.e. divisible by 100), in which case it is a normal year. However if the year is also divisible by 400 then it becomes a leap year. Thus 1600 was a leap year, but 1700 and 1800 were not. This new calendar was known as the Gregorian calendar.

The Gregorian calendar was slowly introduced across Europe, but in England the public were alarmed at the idea of dropping 10 days from the calendar - they believed their life-span was pre-determined, and that removing 10 days from the year would result in everyone dying 10 days early! As a result the Gregorian calendar was not implemented in Britain until 1752, by which time it had become necessary to drop 11 days from the year. More significant as far as genealogists are concerned is that when the Gregorian calendar was introduced in Britain the first day of the New Year was also adjusted. In the Julian calendar New Year's Day had been Annunciation Day on 25th March, but in Britain it was changed to 1st January.

This adjustment in the first day of the New Year causes problems for genealogists. In the Julian calendar 31st December 1700 was followed by 1st January 1700, which means that an individual can appear to die before being born! For example, someone could be baptised on 1st December 1700 and buried on 1st January 1700. However, if the 1752 adjustment of New Year's Day is back-dated, the burial date becomes 1st January 1701, which then makes sense. In order to clarify things some genealogist use what are known as "double dates", in which both the Julian and Gregorian year is expressed. In the example given above the double date for the individual's burial would be 1st January 1700/1701, indicating that while the original parish record might show the burial to have occurred in 1700, it in effect actually occurred in 1701.

On my website I have decided not to use double dates and to simply use the date as stated in the original parish record, where possible. This can result in some unusual events, but I feel that using double dates would make my website look untidy.  Anyone reading these pages should simply add one year to any pre-1752 date between 1st January and 24th March in order to determine the modern equivalent of that date.


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