This is the 8479th most frequent Polish word.
porannego
"Porannego" means "morning" or "of the morning" in English.
In this sentence, 'porannego' is used as an adjective describing 'śniadania' (breakfast), specifying the time-related characteristic of being 'morning'.
Dzisiaj nie miałem czasu na przygotowanie porannego śniadania.
Today I didn’t have time to prepare the morning breakfast.
Here, 'porannego' describes 'SMS-a' (text message), giving the nuance that it was sent or discovered in the morning.
Znalezione porannego SMS-a sprawiło mi dużo radości.
Finding the morning text message brought me great joy.
'Porannego' in this context modifies 'słońca' (sun), indicating the time of day and portraying its characteristic atmosphere.