time thief

plural time thieves

1. idiomaticinformalSomething or someone that consumes an inordinate amount of time, especially without achieving anything productive.

   Trying to change our basic nature is difficult at best, and struggling against it is a time thief.

   2014, Ana Weber, 360 Degrees of Success: Money, Relationships, Energy, Time: The 4 Essential Ingredients to Create Personal and Professional Success in Your Life, Morgan James Publishing, →ISBN, page 141

   2 more examples

   Genie is also an invaluable asset when gabbing on the telephone which can really be a time thief since it's so easy to lose track of time when lost in deep conversation with another.

   2006, Don Boyer, The Power of Mentorship, Real Life Teaching/Publishing, →ISBN, page 137

   In fact, anything we do just to kill time—even essentially healthy activities like reading, chatting on the phone, or completing a sudoku puzzle—becomes a time thief.

   2008, Jan Silvious, Smart Girls Think Twice: Making Wise Choices When It Counts, Thomas Nelson, →ISBN, page 61

   Synonyms: time bandit, time burglar