What time is best for a small registrar office legal ceremony? (with details in post)

Hi everyone! My partner and I are looking into times for our civil ceremony. We anticipate about 15-20 guests total, likely family only. It would be a Saturday in the summer months.

Our ideal time is:

- Civil ceremony
- Couple & group pictures at a nearby park across the road
- Make our way to casual drinks
- Group meal with family
- Meet a small group of our friends after for celebratory drinks (at this point family can go home and rest if they want to! or carry on with us)

We're debating on times between 12 to 2/3pm. Wondering if folks have any advice on how to organize the day? How did you do it? I'm assuming 2hours for ceremony, photos, and making our way to the meal location -- to me it seems like 12pm would imply a late lunch, whereas 3pm would imply an early dinner. Any benefits to choosing one over the other?

Thanks in advance for any thoughts/suggestions!