According to Wikipedia, the correct translation for seasonal-adjustment is „Saisonbereinigung“.

I am not sure about the second phrase (maybe „Saison-Differenzierung“ or „saisonale Unterschiede“?) because I do not know much about the context. If you explain it, I could try to find a better translation.

According to Wikipedia and Oxford dictionary, the correct translation for "seasonal-adjustment" is "Saisonbereinigung".

I am not sure about "seasonal-differencing". As stated by @jarnbjo and DeepL Translator, it seems to be "saisonale Differenzierung". I do not know much about the context, but if you explain it, I could try to find a better translation.

According to Wikipedia, the correct translation for the first phrase is „Saisonbereinigung“. I am not sure about the second phrase (maybe „Saison-Differenzierung“ or „saisonale Unterschiede“?) because I do not know much about the context. If you explain it, I could try to find a better translation.

According to Wikipedia, the correct translation for seasonal-adjustment is „Saisonbereinigung“. 

I am not sure about the second phrase (maybe „Saison-Differenzierung“ or „saisonale Unterschiede“?) because I do not know much about the context. If you explain it, I could try to find a better translation.