Heather Mahalik wrote a detailed blog post on iOS 11 SMS and iMessage artifacts. The blog post “Time Is NOT on Our Side When It Comes to iOS 11 Messages” can be found at www.smarterforensics.com/blog. After discovering that the tools were not correctly parsing messages and/or not correctly decoding the 18-digit Mac datetime stamps, she worked with co-author Lee Crognale (Domenica) to create an SQLite query that will parse this information for you. The query shown above and the script that will parse the sms.db are available on Heather’s GitHub and are included in your VM.¹

Reference:

[1] https://github.com/hmahalik