It is said Jicky was the inspiration for Shalimar, with added vanilin synthetic and hesperidic top notes. Yet, Shalimar is the ultimate oriental, while Jicky is Fougere subtly leaning towards oriental. I wouldn't call them very similar, though. Guerlain are well-known for their vanilla-bases, but in L'Heure Bleue it is done much more subtly than in Shalimar or Jicky. Perhaps they smell similar to you precisely of this base.
L'Heure Bleue is a rich floral that I cannot associate with anything else.
If you are looking for a daytime Guerlain, I'd suggest you also look up Chamade and Vol de Nuit.
Tastes are different, however, you say you see Shalimar as winter fragrance, while I wear Shalimar more in the spring/summer months in the daytime.
L'Heure Bleue is good for any season, but is divine for spring/summer evenings.
But my favourite Guerlain and my holy grail is Mitsouko (fruity chypre), so I have to reccomend that one as well.