Previews of what expect from the Bank of Japan today are here:

On the timing for the announcement - the Bank of Japan does not have a set time.

But … expect the announcement some time between 0230GMT and 0330 GMT. With little if any change expected from the Bank today after July's alterations in policy, the announcement should be earlier in that window rather than later.

Check this out for the basis of the timing prediction:

2016

  • 29 January 12.38pm 0338GMT - added easing (negative interest rate)
  • 15 March 2016 1235pm 0335GMT
  • 28 April 2016 12.01pm 0301GMT
  • 16 June 2016 11.45am 0245GMT
  • 29 July 2016 12.44pm 0344GMT (more easing, added in further ETF purchases)
  • 21 September 2016 1.18pm Tokyo time, 0418GMT (comprehensive review and a stack of new policy moves)
  • 01 November 2016 0254GMT
  • 20 December 2016 0251GMT

2017

  • 31 January 2017 1156AM Tokyo time, 0256GMT (maintains policy steady)
  • 16 March 2017 1154am Tokyo time, 0254GMT (maintains policy steady)
  • 27 April 2017 1214pm Tokyo time, 0314GMT (maintains policy steady, upgraded economic outlook, pushes out inflation forecasts)
  • 16 June 2017 1154am, 0254GMT (maintains policy steady, maintains economic outlook ... boosts its outlook for private consumption)
  • 20 July 2017 1210 Tokyo time 0310GMT (maintains policy steady, upgraded economic outlook, pushes out inflation forecasts)
  • 21 September 2017 0315GMT (maintains policy steady, upgraded assessment on public investment)
  • 31 October 2017 0304 GMT (maintains policy steady ... noob on the Board Kataoka wants more easing!)
  • 21 December 2017 0245 GMT (maintains policy steady ... noob on the Board Kataoka wants more easing ... again. BOJ kept economic assessment unchanged)

2018

  • 23 January 2018 0314 GMT - monetary policy held steady
  • 9 March 2018 0245GMT
  • 27 April 2018 0302GMT - policy held steady, removes phrase on expected timing for hitting price goal
  • 15 June 2018 0241GMT - policy held steady, downgrades its assessment of CPI
  • 31 July 2018 0403GMT - Significant changes made