Does the time difference between Dublin and Jakarta change during the year?

Yes. Because of daylight saving time the gap moves between −7h and −6h.

When is the best time to call Jakarta from Dublin?

Between 09:00 and 11:00 in Dublin, which is 15:00 to 17:00 in Jakarta.

Dublin is 6h behind Jakarta. This gap is not fixed: daylight saving time moves it between −7h and −6h during the year.

Dublin

Ireland

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Jakarta

Indonesia

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A 9-to-5 day in each city overlaps for 2h. That is 09:00–11:00 in Dublin, which is 15:00–17:00 in Jakarta.

City	Time zone	UTC offset
Dublin · Ireland	Europe/Dublin	UTC+1
Jakarta · Indonesia	Asia/Jakarta	UTC+7

What is the time difference between Dublin and Jakarta?: Dublin is 6h behind Jakarta. This gap is not fixed: daylight saving time moves it between −7h and −6h during the year.
Does the time difference between Dublin and Jakarta change during the year?: Yes. Because of daylight saving time the gap moves between −7h and −6h.
When is the best time to call Jakarta from Dublin?: Between 09:00 and 11:00 in Dublin, which is 15:00 to 17:00 in Jakarta.