observed

verb

1. (form-of, participle, past)simple past and past participle of observe

   “Aldrichimica Acta Volume 30 No 4 (pdf) from Sigma-Aldrich N-substituted pyrroles are much less reactive than the other 5-membered 1,3-dienes; no reaction was observed between N-(trimethylsilyl) pyrrole or N-benzylpyrrole with Smith’s diene (4) under thermal or high pressure (4 days at 14 kbar) conditions, even in the presence of Lewis acids.”

adj

1. Exceptionally celebrated on a date other than the usual date.

   “Sunday, July 1: Canada Day; Monday, July 2: Canada Day observed.”