Representative implementations of devices and techniques provide bipolar time-to-digital conversion. For example, either a positive time duration or a negative time duration may be converted to a digital representation by a linear time-to-digital converter (TDC). A set of logic functions may be applied to the input of the TDC to provide start and/or stop signals for the TDC. Further, a correction component may be applied to an input or an output of the TDC to compensate for a delay offset of the TDC.