He started work on Calarel around January 2023 and the full release was at the end of December 2024, so 2 years give or take a few days. Another thing of note is that his last WIP post for Calarel was 5 months before the official release at the start of August last year.
His first "official" post related to Girls Night Out was at the start of July this year but, from the wording in the description of that post and from content in previous pinups before that post, he definitely started work on it as early as June if not earlier. So, being a little generous, he's been working on Girls Night Out for around 8 months. Working off all that plus the fact that he's already posted the final set of WIPs for the project, I wouldn't be surprised if the full release was still like 6 months away to be honest.