Disadvantages of thermoluminescence dating
In the period 4 January to 28 December the ISO week year number is always equal to the Gregorian year number. The ISO 8601 definition for week 01 is the week with the Gregorian year's first Thursday in it.
The days differing are a Friday through Sunday, or a Saturday and Sunday, or just a Sunday, at the start of the Gregorian year (which are at the end of the previous ISO year) and a Monday through Wednesday, or a Monday and Tuesday, or just a Monday, at the end of the Gregorian year (which are in week 01 of the next ISO year).
Method: Multiply the week number by 7, then add the weekday.
From this sum subtract the correction for the year.
The Gregorian leap cycle, which has 97 leap days spread across 400 years, contains a whole number of weeks ().
In every cycle there are 71 years with an additional 53rd week (corresponding to the Gregorian years that contain 53 Thursdays).A precise date is specified by the ISO week-numbering year in the format from 1 through 7, beginning with Monday and ending with Sunday.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).The main relative dating method is stratigraphy (pronounced stra-TI-gra-fee), which is the study of layers of rocks or the objects embedded within those layers.