Abstract：Low-mass stars form via gravitational collapse of molecular cloud cores.  Although their formation has received considerable attention in the last few decades, the rate at which a star gains most of its mass and the physics that drives the main phase of stellar growth is still not understood. Most protostars have luminosities significantly fainter than the luminosity expected from steady accretion over the protostellar lifetime.  The solution to this problem may lie in episodic mass accretion ---- prolonged periods of very low accretion punctuated by short bursts of rapid accretion.  However, the timescale and amplitude for variability at the protostellar phase is almost entirely unconstrained. Our long-term East Asia Observatory JCMT/SCUBA2 sub-mm monitoring program of eight nearby star forming regions, the first large sub-mm variability program, is measuring accretion variability of protostars to understand the physics of the disk instabilities that drive this variability.  To date, we have detected one periodic variable and identified ~10% of embedded sources as variable at the ~5%/year level.  This program is laying the technical and scientific groundwork for a more ambitious and powerful program that could be implemented with a 60-m sub-mm telescope.