Is the word cedo the same in Brazilian and European Portuguese?

Yes

The word "cedo" has the exact same meaning (early) and grammatical function (adverb) in both Brazilian and Continental Portuguese. The only difference lies in pronunciation. In Brazilian Portuguese, the vowels tend to be more open and clearly articulated. In Continental Portuguese, the vowels are often more closed or even reduced; for example, the "e" may sound more like [sedu] rather than the slightly more open [sɛdu] often heard in many Brazilian dialects, and the final "o" is typically more closed and subtle.

Brazilian Portuguese Examples

1. Acordei muito cedo hoje. (I woke up very early today.)
2. A gente precisa sair cedo para não pegar trânsito. (We need to leave early to avoid traffic.)
3. Ele sempre chega cedo no trabalho. (He always arrives early at work.)
4. Não chegue tão cedo, a loja ainda está fechada. (Don't arrive so early, the store is still closed.)
5. Você costuma dormir cedo? (Do you usually sleep early?)

Continental Portuguese Examples

1. Acordei muito cedo hoje. (I woke up very early today.)
2. Temos de sair cedo para evitar o trânsito. (We have to leave early to avoid traffic.)
3. Ele chega sempre cedo ao trabalho. (He always arrives early at work.)
4. Não venhas tão cedo, a loja ainda está fechada. (Don't come so early, the store is still closed.)
5. Costumas deitar-te cedo? (Do you usually go to bed early?)