Time change reminder --- March / April 2021

Over the next 3 weeks, various countries will begin (or end) Daylight Saving Time (DST), turning their clocks forward or back, as the case may be — and, in the process, shifting their trading session times forward or back – by one hour.

Then, in the Fall, all these time changes will be reversed on various dates, beginning in late September.

We have been tracking these time changes for several years, and by now you know how to make the necessary adjustments in your trading. All you need is a schedule of the changes which are coming.

Here’s the schedule:

Daylight Saving Time Changes for March-April 2021 in the major forex markets

  • March 14 — the US and Canada will begin Daylight Saving Time

  • March 28 — the UK, and eastern, central and western Europe will begin Summer Time (DST)

  • April 4 — southeastern Australia (Sydney, Melbourne, Canberra, Hobart, etc.)
    and New Zealand will return to Standard Time

Daylight Saving Time Changes in other markets

  • March 28 — Ireland will begin Summer Time (DST)

  • April 4 — most of Mexico will begin Daylight Saving Time

Significant markets which do not observe Daylight Saving Time — listed by forex market size
(figures in parentheses are daily forex trading volumes in billions of USD — source: BIS 2019)

  • Singapore (633), Hong Kong (632), Japan (376), and China (136)

Other markets which do not observe Daylight Saving Time

  • Korea (55), Russia (47), United Arab Emirates (46), India (40), Taiwan (30), South Africa (20),
    Turkey (19), Brazil (19), Thailand (14), and Malaysia (10)

See post #2 for details of the time changes which will occur in the US and Canada this weekend.

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Note regarding the start of DST in the US and Canada –

In previous years, the US and Canada have begun DST on the first Sunday in March, three weeks ahead of the UK and EU. This year, for reasons not widely publicized, the US and Canada will begin DST on the second Sunday in March, two weeks ahead of the UK and EU. As in previous years, the UK and EU will begin DST on the last Sunday in March.


On Sunday, March 14, the US and Canada will begin Daylight Saving Time (DST).

Six time zones in the US (including Alaska and Hawaii), and seven time zones in Canada (including the maritime provinces of New Brunswick, Nova Scotia, and Newfoundland), will be affected by this time change.

In the eastern US and Canada, which includes the key New York market, the time zone will change from UTC-5 to UTC-4.

Clocks in the US and Canada (and in Bermuda, Bahamas, and Cuba) will be turned forward one hour prior to the opening of the forex market on Monday morning, March 15.*

  • For traders in the US and Canada, the New York Session times will not change, but the trading sessions in every other forex market will open and close one hour later than previously, starting Monday morning, March 15.* (see the Note, below).

  • For traders in all other countries, the only change will be that the New York Session will open and close one hour earlier than previously, starting Monday morning.

*Note – These statements do not apply to Hawaii, most of Arizona, and certain portions of Canada, because those places do not observe DST.

This change will temporarily alter the normal time difference between London and
New York, as follows:

  • For the next 2 weeks — from Sunday, March 14, through Friday, March 26 —
    the London/New York time difference will be 4 hours (instead of the usual 5 hours).

  • And, during this same 2-week time period, the heavily-traded London/New York Overlap
    will be 5 hours (instead of the usual 4 hours), as follows: 12pm-5pm London time,
    and 8am-1pm New York time.


The next DST time change will occur in 2 weeks, on March 28, at which time the UK and all of eastern, central, and western Europe will begin Summer Time (daylight saving time).

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On Sunday, March 28, the UK and all of eastern, central and western Europe will begin Summer Time (what we, in the US, call Daylight Saving Time - DST).

This time change will involve every country situated between the Atlantic Ocean and the Russian border, except Belarus.

Listed geographically, from west to east —

  • In western Europe (Ireland and Portugal), and in the UK (including the Channel Islands),
    the WET and GMT time zones will change to WEST and BST (both UTC+1), respectively.

  • In central Europe (30 countries and principalities from Spain east to Serbia, and from Sweden south to Malta), the CET (UTC+1) time zone will change to CEST (UTC+2).

  • In eastern Europe (Finland, Estonia, Latvia, Lithuania, Ukraine, Moldova, Romania, Bulgaria, Greece, and Cyprus), the EET (UTC+2) time zone will change to EEST (UTC+3).

Clocks in all of these countries will be turned forward one hour, prior to the opening of the forex market on Monday morning, March 29.

  • For traders in all of these countries, opening and closing times in the London Session and in the European Session will not change, but the trading sessions in Tokyo and New York will begin and end one hour later than previously, starting Monday morning.

  • For traders in countries not listed above, the only change will be that the London Session and the European Session will begin and end one hour earlier than previously, starting Monday morning.

This change will restore the normal time difference between London and New York,
as follows:

  • Beginning on Monday morning and continuing until September, the time difference between London and New York (which has been 4 hours in duration for the past 2 weeks) will return to its normal 5-hour duration.

  • Also beginning Monday morning, the heavily-traded London/New York Overlap Period will return to its normal 4-hour duration: 1 pm-5 pm London time, and 8 am-12 pm New York time.


The last DST time change for this season will occur in one week, on April 4, at which time New Zealand and southeastern Australia will return to Standard Time.

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On Sunday, April 4, New Zealand and southeastern Australia will end Daylight Saving Time (DST),
and will return to southern hemisphere Standard Time.

  • In New Zealand, the NZDT time zone (UTC+13) will change to NZST (UTC+12).

  • In the Australian states of New South Wales, Victoria, ACT, and Tasmania (Sydney, Melbourne, Canberra, Hobart, etc.), the AEDT time zone (UTC+11) will change to AEST (UTC+10).

  • In South Australia (Adelaide, etc.), the ACDT time zone (UTC+10½) will change to ACST (UTC+9½).

Clocks in New Zealand and in southeastern Australia will be turned back one hour, prior to the opening of the forex market on Monday morning, April 5.

  • For traders in New Zealand and in southeastern Australia, the forex trading sessions in Wellington and Sydney will not change, but the trading sessions in Tokyo, Zurich, London, and New York will begin and end one hour earlier than previously, starting on Monday morning.

  • For traders in the rest of Australia, and in all other countries, the only change will be that the forex trading sessions in Wellington and Sydney will begin and end one hour later than previously, starting on Monday morning.


Also on April 4, most of Mexico will begin DST.


These are the last time changes for this season. The next time change will occur in late September 2021