Roblox join dates are commonly shown in ISO 8601 when pulled from the account data itself, like YYYY-MM-DD or sometimes YYYY-MM-DDTHH:MM:SSZ. On the profile page, though, the display can be localized and may appear as MM/DD/YYYY or DD/MM/YYYY depending on region or account settings.

What that means

  • Raw API / data format: usually ISO 8601, for example 2014-02-03T19:16:57.357Z.
  • Profile display format: can vary by locale, with some users seeing MM/DD/YYYY and others DD/MM/YYYY.
  • Join date location: Roblox says the join date appears in the Statistics Box on your profile.

Simple example

If you see 2014-02-03T19:16:57.357Z, the date part is 2014-02-03, which means year-month-day.

TL;DR

The Roblox join date is typically stored in ISO 8601 (YYYY-MM-DD), but the visible format on the site may be localized to your region.