The theory and applications of fractional differential equations are gaining relevance since they are used in the modeling of different processes in physics, chemistry, and engineering.

Time-scale formalism unifies the theories of difference and differential equations. Therefore, time-scale analysis constitutes a good tool to study both discrete and continuous systems.

Recently, several attempts have been done to join the two subjects, developing a fractional calculus on time scales. The subject is still much evolving, and contributions joining the two areas are particularly welcome.

In order to apply fractional and/or time-scale differential equations for solving real problems, we need to add some uncertainty in the modeling. Therefore, often, problems are set-valued, for example, interval, fuzzy, or stochastic problems. Sometimes, combinations can be applied for different types of fractional and/or time-scale differentiability.

The special issue is focused on latest results in fractional and/or time-scale differential equations and their applications. Potential topics include, but are not limited to:

• Set-valued ordinary and partial differential equations
• Set-valued equations on time scales
• Fractional set-valued differential equations
• Equations with impulses
• Calculus of variations and optimal control with time-scale and/or fractional derivatives
• Interval and fuzzy fractional/time-scale differential equations
• Stochastic set-valued differential systems with error analysis
• Existence, uniqueness, and stability of solutions
• Numerical simulations and computational aspects
• Fractional impulsive differential equations with uncertainty
• Fractional/time-scale numerical methods with uncertainty
• Local fractional operators
• Applications of fractional and/or time-scale calculus
• Applications to real world problems

Before submission authors should carefully read over the journal’s Author Guidelines, which are located at http://www.hindawi.com/journals/aaa/guidelines/. Prospective authors should submit an electronic copy of their complete manuscript through the journal Manuscript Tracking System at http://mts.hindawi.com/submit/journals/aaa/frats/ according to the following timetable: