long date at is used to determine the date of a particular sample and presents it using the full name of the month and four digits for the year. For example, given the following case fragment:

           01 Jun 03    20 Jun 03    03 Sep 03    15 Oct 03    02 Nov 03
ABC           2.5          2.3          2.2          2.1          2.0
DEF           6.3                       4.0          1.9


long date at second most recent DEF is “15 October, 2003”

long date at first ABC is “1 June, 2003”

long date at max DEF contains “June”