As discussed in a number of sources, a leap second is being added on June 30. Here's how to prepare your copy of GMAT:

 

  1. Review the GMAT User Guide on the subject.

  2. Download the updated US Naval Observatory leap second file:
    tai-utc.dat 

  3. Overwrite GMAT's old file with this new copy:

    <GMAT>\data\time\tai-utc.dat


  4. Download the updated NAIF leap second file:
    naif0011.tls 

     

  5. Place this file in your GMAT data folder:
    <GMAT>\data\time\naif0011.tls


  6. Modify your GMAT startup file (<GMAT>\bin\gmat_startup_file.txtto point to the new NAIF file:

    LSK_FILE               = TIME_PATH/naif0011.tls
  7. Restart GMAT.

 

That's it! If you have any issues, post to any of our help resources: