A B747-200 CREW QUESTIONED THE TERMINOLOGY THE CTLR USED FOR VECTOR HDGS TO AVOID A CONFLICT.

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FLYING A B747-200 AT FL370; FROM ZZZ TO JFK. ENRTE TO AIR (BELLAIRE) WE WERE RERTED AND SENT NORTHWARD TOWARDS JHW (JOHNSTOWN). ZOB INSTRUCTED US TO TURN L FOR TFC; AND WE TURNED TO 330 DEGS. AFTER A FEW MOMENTS; WE WERE ASKED OUR PRESENT HDG (WE ACKNOWLEDGED THE INITIAL CALL TO TURN 30 DEGS L) AND TOLD HIM. THE CTLR THEN GAVE US A VECTOR OF 030 DEGS; TURNING US R 60 DEGS FOR TFC AVOIDANCE. MY CREW AND I WERE SURPRISED BY THE WIDELY VARYING VECTORS RECEIVED IN SUCH A SHORT TIME SPAN; PERHAPS 30 SECONDS ELAPSED BTWN VECTORS. WE HAD NO TCASII INDICATIONS AND 1 CREW MEMBER HAD A VISUAL ON TFC THAT WAS NOT A FACTOR. THERE MAY HAVE BEEN SOME CONFUSION ON THE CTLR'S PART AND/OR OUR PART IN THE INSTRUCTIONS AND READBACK OF HDGS THAT CAN SOUND SIMILAR. 'TURN 30 L;' OR TURN '030' CAN SOUND THE SAME; BUT IF YOU ARE HDG 360 DEGS; IT'S MARKEDLY DIFFERENT. SIMILARLY; '030' OR '330' CAN SOUND SIMILAR WHEN RECEIVED OR SPOKEN. RECOMMEND WE CONSIDER USING PHRASEOLOGY USING TWENTY; THIRTY; FORTY; ETC; SUCH AS VECTOR 'THREE THIRTY DEGS' OR VECTOR 'THIRTY DEGS' TO DIFFERENTIATE. AN ADDITIONAL FACTOR WAS THAT THE CREW WAS TIRED; HAVING RPTED FOR DUTY AT XB45; ALMOST 13 HRS EARLIER; WITH MINIMUM ACTUAL REST THE EVENING BEFORE; DESPITE HAVING AN 8 HR REST PERIOD. THIS WAS THE FIRST LEG OF A PATTERN OF FLYING; SO GETTING UP AT XA15 REQUIRED EACH OF US TO TRY AND GO TO SLEEP MUCH EARLIER IN THE EVENING THAN WE WERE ACCUSTOMED.