%% You should probably cite draft-ietf-ntp-implementation-guidance instead of this I-D.
@techreport{aanchal-time-implementation-guidance-00,
    number =    {draft-aanchal-time-implementation-guidance-00},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-aanchal-time-implementation-guidance/00/},
    author =    {Aanchal Malhotra and Martin Hoffmann and Willem Toorop},
    title =     {{On Implementing Time}},
    pagetotal = 9,
    year =      2017,
    month =     oct,
    day =       30,
    abstract =  {This document describes the properties of different types of time values available on digital systems and provides guidance on choices of these time values to the implementors of applications that use time in some form to provide the basic functionality and security guarantees.},
}