You need to visit the Darigan Pteri's lookup at any time within the 24-hour span that it is 644 days old (listed on the lookup). The below times are approximations, with a 30 minute span of error.
dciiidc:
April 20, 2010, 9 am
pitri_duba
May 30, 2010, 3 pm
mod13lk
June 9, 2010, 2 pm