Definitions for timeserving
Random House Webster's College Dictionary
a person whose conduct is shaped to conform to the opinions of the time or of persons in power, esp. for self-serving ends.
Origin of timeserver:
opportunist, opportunistic, timeserving(adj)
taking immediate advantage, often unethically, of any circumstance of possible benefit
A variant of time-serving.
obsequiously complying with the spirit of the times, or the humors of those in power
an obsequious compliance with the spirit of the times, or the humors of those in power, which implies a surrender of one's independence, and sometimes of one's integrity