Export FormatTimestamp for emitting the postgres timestamp format
Export FormatTimestamp for emitting the postgres timestamp format

This is a dual to ParseTimestamp exported in 3cd0097, and is needed
for CockroachDB.

ympons/pq,bugreplaydev/pq,jnewmano/pq,bugreplaydev/pq,ympons/pq,VividCortex/pq,lib/pq,jnewmano/pq