Czywczynski says he will make a decision after reviewing the offers made by 1 May deadline.
The OPCW executive council has set a 1 November deadline for the destruction of chemical weapons production.
There was no deal approved by Congress and signed by President Obama before the 1 January deadline.
He completed visa and registration arrangements before the RFU Championship's 1 March deadline.
United intend to appeal against the Football Disciplinary Commission decision before the 1 May deadline.
A spokesman noted that it had acted ahead of a 1 June deadline.
He will confirm a replacement for Richards before the 1 June deadline.
The dreaded 1 March deadline has come and gone, and the sequester is in full effect.
The shutdown began when Congress missed a 1 October deadline to pass a budget.
Meanwhile, the government remains partially shut down because Congress failed to agree on funding by a 1 October deadline.
But researchers in the engineering systems community responded enthusiastically, submitting 60% more proposals than usual by the 1 October deadline.
