CalendarRules is a rules-based deadline calculation service for law firms, corporate legal departments, and legal software providers, built around the ongoing maintenance of court and agency rule sets.

Key features and functions include:

Court Rules Coverage
The platform maintains rule sets covering federal, state, bankruptcy, appellate, local, judge-specific, and agency rules, with coverage available in all 50 U.S. states.

Date and Docket Calculators
Standalone Date Calculator, Docket Calculator, and Docket Research tools allow users to input case information and receive calculated deadlines directly, without a separate case management system.

Rule Update Distribution
Rule changes are pushed centrally so that subscribers' calculated dates reflect current court rules without requiring manual updates on the user's end.

Third-Party Integrations
CalendarRules rules content is embedded within a number of legal case management, docketing, and practice management systems, including Clio, MyCase, Litify, SimpleLaw, MerusCase, CASEpeer, JuraLaw, LawBase, Legal Files, CourtAlert, CourtDrive, Docket Alarm, DocketCalendar, AdvoLogix, SimpleLegal, Tabs3/PracticeMaster, SmartAdvocate, CaseRoads, Clarra, CaseFlow, BEC Docket Enterprise, Coyote Analytics, CityLaw/CountyLaw, MatterAlert, HoudiniEsq, and Legal Software Systems.

Calendar Sync
Calculated deadlines can sync to Microsoft Outlook and Google Calendar.

Ownership by Clio
CalendarRules was spun out of OpenText in October 2007 by a team with prior experience building LegalKEY's Critical Dates product. In June 2021, the company was acquired by Clio (Themis Solutions Inc.), which continues to operate CalendarRules under its original branding.