Afrikaans to English Social Sciences Religion

Good afternoon, I'm trying to understand an announcement concerning military chaplain service in South Africa.

I've translated the following sentence:

Afgesien van hulle diens in die eenhede, sal elkeen van die teologiese offisiere ook vir ’n tydperk van drie maande grensdiens doen.

Apart from their service in units, each of the theological officers also will be responsible for limited service for a period of three months.

Am I on the right track? Could service refer to military service? Thank you for clarifying!