Hi Srinu,
I hope this is the explanation you're looking for:
If you populate all dates (early, late, pickup and delivery) it will respect all dates.
Example:
Your pickup time window is telling you to pick it up at day 1 (early and late pickup date or on the same day but tim eis different).
You delivery time window is telling you to deliver from day 10 to day 12.
Your transit time is 3 days.
A shipment is build to start at day1 and will be delivered at day 10. Even that the transit time is shorter.
In this case you can still move around with the delivery date (via shipment actions) to day 11 or 12 without getting a warning of invalidness.
I have to say that this is the case with the "Date Emphasis" at BOTH.
Help says:
Date Emphasis governs how important the date sets are. The options are BOTH, SHIP, DELV, PAST, NONE.
Choose
BOTH to look at the available dates and the delivery dates.
Choose
SHIP to look at the available dates and set the delivery dates out to infinity.
Choose
DELV to look at the delivery dates and consider the available dates to be now.
PAST is acting differently and can have "unexpected" results. Here you always want to have dates populated, otherwise your shipment will be built a year back.
Hope this helps.
Best regards,