Nick Jr. is seen on Nickelodeon weekday mornings from 9AM to 2PM ET. Summer hours may vary, with Nick Jr. starting as early as 9AM ET and ending as late as 12PM ET, depending on the time of the season and other shows scheduled. It is aimed at a preschool-age audience.





Buildup
Before 1981, many shows that might be associated with a preschool audience were broadcast on Nickelodeon, but were not specifically distinguished in their own programming block. Most preschool programs were shown roughly between the hours of 8 AM and 3 PM Eastern, which approximates the hours in which older children might be in school.


1981–1994

By the end of 1981, the Nick Jr. brand was in place and in use, with an approximate six hour portion of the Nickelodeon broadcast day, from 9 A.M. to 3 P.M. Eastern time.

The logo for the new Nick Jr. brand became a distinctive feature for the block. While Nickelodeon used a completely orange logo, Nick. Jr. used an orange 'Nick' and a light blue 'Jr', with the blue always smaller than the orange. The logo typically depicted a parent, or older sibling, and child, but varied in the shape or species (e.g. two rabbits, two simplified human figures, two trees), which remains in use today.


Eureeka's Castle,One of the first Nick.Jr Series in 1989


Until 1989, a former staple of the Nickelodeon lineup, Pinwheel was featured, and eventually replaced by Eureeka's Castle. Much of the remaining time in the lineup, particularly early in this time period, was devoted to animated series, many of which were of foreign origin (David the Gnome, Noozles, The Adventures of the Little Koala, The Little Prince). Programming in the vein of live action and puppeted preschool programming also appeared during this time.

Part 2 coming soon!
P.S. Sorry I have a couple pictures.I couldn't find that much of pictures