Advantages and disadvantages of thermoluminescence dating
To put it simply, certain minerals (quartz, feldspar, and calcite), store energy from the sun at a known rate.
This energy is lodged in the imperfect lattices of the mineral's crystals.
If it is on a Sunday, it is part of week 52 of the previous year. If it is on a Thursday, it is in week 53 of the year just ending; if on a Friday it is in week 52 (or 53 if the year just ending is a leap year); if on a Saturday or Sunday, it is in week 52 of the year just ending.
The long years, with 53 weeks in them, can be described by any of the following equivalent definitions: All other week-numbering years are short years and have 52 weeks.
This was previously known as "Industrial date coding".
The system specifies a week year atop the Gregorian calendar by defining a notation for ordinal weeks of the year.
The number of weeks in a given year is equal to the corresponding week number of 28 December, because it is the only date that is always in the last week of the year since it is a week before 4 January which is always in the first week of the year.
For example, the Gregorian date 31 December 2006 corresponds to the Sunday of the 52nd week of 2006, and is written 2006-W52-7 (in extended form) or 2006W527 (in compact form).
Method: Multiply the week number by 7, then add the weekday.
From this sum subtract the correction for the year.
That is 364 or 371 days instead of the usual 365 or 366 days.
The extra week is sometimes referred to as a leap week, although ISO 8601 does not use this term. Each week's year is the Gregorian year in which the Thursday falls.If 1 January is on a Friday, it is part of week 53 of the previous year.If it is on a Saturday, it is part of the last week of the previous year which is numbered 52 in a common year and 53 in a leap year. This week’s properties are: If 31 December is on a Monday, Tuesday or Wednesday, it is in week 01 of the next year.The US broadcast calendar counts the week containing 1 January as the first of the year, but otherwise works like ISO week numbering without partial weeks.