045 Subfield $b - Formatted 9999 B.C. through C.E. time period:

Subfield $b contains a specific time period formatted as yyyymmddhh, preceded by a code for the era (c for B.C.; d for C.E.).  The era and year are required components; the month, day, and hour are optional.

era expressed as a code:  c (B.C.); d (C.E.).

year expressed as a four-digit number (0000 to 9999) right justified; unused positions contain zeros.

month expressed as a two-digit number (01 to 12) right justified; unused positions contain zeros.

day expressed as a two-digit number (01 to 31) right justified; unused positions contain zeros.

hour expressed as a two-digit number using the 24-hour clock (00 to 23) right justified; unused positions contain zeros.

First indicator position values 0-2 specify whether the time period in subfield $b is a single date, multiple dates, or a range of dates.  Each 9999 B.C. through C.E. time period associated with the heading is contained in a separate subfield $b.

Examples:

651  #0  $aFrance$xHistory$yRevolution, 1791-1797.

045  2#  $bd1791$bd1797

651  #0  $aJapan$xHistory$yFebruary Incident, 1936 February 26)

045  0#  $bd19360226

651  #0  $aChina$xHistory$y221 B.C.-960 A.D.

045  2#  $ad7n6$bc0221$bd0960

To return, select:

045  Time Period of Content