cdm/src/main/java/ucar/nc2/units/SimpleUnit.java
static public boolean isDateUnit(String unitString) {
    SimpleUnit su = factory(unitString);
    return su != null && isDateUnit(su.getUnit());
  }
static public boolean isDateUnit(String unitString) {
    SimpleUnit su = factory(unitString);
    return su != null && isDateUnit(su.getUnit());
  }
Return true if the given unit is convertible to a date Unit.
allowed format is something like:
<pre>[-]Y[Y[Y[Y]]]-MM-DD[(T| )hh[:mm[:ss[.sss*]]][ [+|-]hh[[:]mm]]]</pre>

@param unitString check this unit string
@return true if its a Date