Parameters in Redash have editable settings. In order to get to the settings menu, you have to click on the settings icon in the param box:

Once clicked, it will open a Parameter Settings menu, where you can control the title, type of parameter, and set whether it's Global. We will explain all of these settings shortly:

• Title: By default, it's just the param name that you gave it in the query, but you can always change it to something more meaningful for others (and for yourself).
• Type: The data type of the parameter (also affects the behavior of the param box UI). Its currently available types are Text, Number, Dropdown List, Query Based Dropdown List, Date, Date and Time, Date, and Time (with seconds), Date Range, Date and Time Range, Date and Time Range (with seconds).
  The Date Ranges - were introduced starting v5in addition with the support for Now/Today as default value of Date/Time parameter type.
• Global: When set (checkbox), the same parameter can be shared across multiple queries (the parameter in those queries must have the same name, and marked in all the queries as global). If not set, every query has its own parameter, even if the parameters have the same name!