Tasks using Edays or assigned 365 day calendars and the Critical Path

[n]

In an effort to have tasks which ignore all weekends and holidays on
the critical path identified as such by MS Project, I have found that
using edays causes MS Project to identify the task as non critical. To
work around this I defined a 365 day calendar and returned to the use
of days not edays. However, the task is still not identified as being
on the critical path. The task which is on the 365 calendar (and
critical path) starts on Wednesday 8:00 am; its predecessor, also on
the critical path but no longer identified as such, ends on the
preceding day at Tuesday 5:00 pm. There is a total slack of two days
(960 minutes) which I believe is causing MS Project to not identify
them as being on the critical path (free slack = 0). Although 5:00 pm
to 8:00 am is only 15 hours (not 16 hours = 2 days) it appears that
this period of time is the source of the slack. If I employ a FS
relationship with a minus 1 min lag (the predecessor now ends at 4:59
and the successor now starts at 5:00 pm the same day not 8:00 am the
next day) the problem goes away and the critical path is restored.

There are no resources assigned.

Is there a more technically appropriate way to address this problem?

 

[Ben Howard]

Interesting, if I set up a task 1 day with a FS relationship to another task
with 365eds, both tasks are defined as critical. If I change the 1st task to
1ed then the tasks remain as critical - I cannot replicate your problem. Are
you able to provide any additional information?