Wednesday, 27 May 2015

Measurement Tools

The following tools support conversion of height/weight measurements and the manipulation of dates. They were originally used in Like Father, Like Son in order to convert between metric and imperial units, and to subtract a mixed-unit age from a date. I'm including them on a blog page — somewhat unusually — so that others might benefit from them.

There are similar tools available on the Internet, with both better and worse user interfaces, but this page provides quicker access to them as a group. I might also include extra tools if anyone makes a good suggestion.

Convert between feet/inches and metres

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feet inches
Converts a height in feet and inches to one in metres, or vice versa.

Convert between stones/pounds and kilograms

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  stones pounds
Converts a weight in stones and pounds to one in kilograms. Also converts kilograms to either stones and pounds, or just pounds. NB: 1 stone = 14 pounds.

Convert between miles/yards and kilometres

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  miles yards
Converts a distance in miles and yards to one in kilometres. Also converts kilometres to either miles and yards, or just yards. NB: 1 mile = 1760 yards.

Count the days between two dates

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Start Date
End Date
  inclusive (adds 1 day)
0 days
Calculates the number of days between the selected dates. The dates may be in either order. NB: Any difference shown as years and days takes account of actual leap years, and is not calculated by simply dividing the day-count by 365.

Offset a base date to find a new date

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Base Date
Resultant Date
Adds or subtracts a duration from a base date to get another date. The duration may include any combination of years, months, weeks, and days. Can also be used to find the day-of-week for a given date by setting the duration to zero.

Calculate range of possible birth dates given an age

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Date Recorded
Year multiple of 5
Resultant Range
Calculates the possible birth dates given an age and a date-of-recording. For instance, a census, a death certificate, or a marriage certificate. The age may be provided in years and/or months, but note that a non-zero months value implies greater accuracy. For instance, 12 months is considered more accurate than 1 year. The age is normally at "last birthday", but may be "next birthday", say for the early Canadian census years. The year can also be rounded down to the previous multiple of 5, say for the 1841 census of England and Wales.