The retention period for Microsoft Entra (Azure AD) sign-in logs depends on the license (Free, P1, P2).
Microsoft's data retention documentation states that with a Microsoft Entra ID P1 license, sign-in data is retained for 30 days.
The relevant table in the "Microsoft Entra data retention" documentation shows:
* With Entra ID P1 or P2: sign-in activity is retained for 30 days
* (With Free tier, sign-in logs are retained for 7 days)
Therefore, under your scenario (tenant has ID P1 license), the logs are available for 30 days.