Tapping and holding on the Maps page will display a pop-up with information on Special Use Airspace (SUA), if present at that location. Within this pop-up, the listed "times of use" are in local time.
If you are viewing SUA on a chart collar, please check the legend for any notes on whether the times of use are listed as local or Zulu. Typically, times of use are listed in local time on VFR sectionals, and in Zulu (UTC) time on IFR charts.
Image 1. SUA times of use shown in local time in the pop-up and the VFR sectional collar.
Image 2. VFR Sectional legend specifying that SUA times of use are in local time.
Image 3. IFR Low chart legend specifying that SUA times of use are in UTC unless otherwise indicated.