Definitions of today:

• noun:   the day that includes the present moment (as opposed to yesterday or tomorrow)

  Example: "Today is beautiful"

• noun:   the present time or age

  Example: "The world of today"

• adverb:   on this day as distinct from yesterday or tomorrow

  Example: "I can't meet with you today"

• adverb:   in these times

  Example: "Today almost every home has television"