National Institute Of
DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING
Multi Time Zone System
KEITH PERES DA COSTA
“We must use time wisely
and forever realize that
the time is always ripe to
----- NELSON MANDELA
The Indian landmass has a longitudinal
span ranging from 68°7' east to 97°25'
east. This accounts for a 2 hours difference
in time between the easternmost and
India currently adheres to a single time
zone policy for whole country, the time
along 82.5° east longitude is set as the
Indian Standard Time (IST), 5 and a half
hours ahead of the Coordinated Universal
Drawbacks Of the Current Approach
A shortcoming with the current IST system is evident considering the
North-Eastern states. If the Sun were to rise at 5:30 am (IST) in the
summer, it would be actually be rising almost an hour earlier in the NorthEastern states, this would lead to a loss of one precious hour of sunlight
and increase in the usage of artificial lighting in the evenings.
Having one Time Zone, also means that the peak demand for energy
across various parts of the country occurs simultaneously, pressurizing
the power station bus bars. This policy, without the use of Daylight
Savings Time (DST) is responsible for consumption of a considerable
amount of energy, which otherwise could have been saved.
Policies Adopted By Other Nations
Russia has eleven time zones, the USA and Canada each have six, Brazil
has four and Australia has three. These countries advance their clocks
during the summer, so that evenings have more daylight and mornings
The per capita average annual domestic electricity consumption in India
as of 2009 was 96 KWh in rural areas and 288KWh in urban areas. This
is highly in contrast to the worldwide per capita annual average of 260
KWh and 6200KWh in the European Union. Thus it is evident that in India
people are still highly dependent on natural light i.e. sunlight and hence a
Multi Time Zone System in India, would be much more effective in energy
saving as compared to that in highly developed Nations.
Related Proposals And Their Drawbacks
Daylight Savings Time (DST) : The practice of shifting the time ahead during
the summer and back again in the winter in order to utilize the maximum
amount of sunlight is Daylight Savings Time (DST).
India is a tropical country, with the Tropic of Cancer dividing the landmass
in roughly two equal parts; the variation of sunlight is not very drastic.
Implementation of DST would be quite difficult in India; as setting clocks
forward and backwards two times annually would be a daunting task in a
country with a massive population, having the largest illiterate population.
Shifting IST ahead by 30 minutes : Shifting Indian Standard Time
permanently to Coordinated Universal Time (UTC) +6.
Western parts of the country would experience sunrise at later times,
raising demands for artificial lighting especially during the winter. In
comparison to the North-Eastern states, the power consumption which is
in direct proportion to the population is considerably higher in the Western
States, rendering this proposal not very energy saving.
As per the TERI survey conducted the net energy savings from
implementing this proposal was estimated to be in the range of 1.02 to
1.10 billion units which is a mere 0.14-0.15 %.
The methodology adopted in the MTZS is on two fronts:
Grid peak load shedding due to time shift.
Reduced energy units consumption due to maximized utilization of
Load Curves Analysis
Domestic and irrigation sector demand curves are dependent on day
light, traditional activities.
Rural and semi urban regular activities also tend to follow day light based
Urban regular activities tend to follow time base.
The MTZS in this front aims to :
Encourage rural and semi urban activities to sync with day light in order to
obtain reduced electricity consumption
To attain a near unity grid diversity factor in Urban areas i.e. similar demand at
all operating points.
Consider two places i.e. place A and place B, both receiving power from
the same dispatch.
Assume that place A is 1 hour ahead of place B in time.
Load curves without MTZS
Length of time falling under
area due to UTC
State boundary stretch (in minutes) wrt IST(Indian
West Side of IST
East Side of IST
falling wrt IST
Jammu & Kashmir
Indian States, longitudinal span and time slot either side of IST
India Population density Map
State Wise Energy Consumption during 2011-2012
A two time zone system approach could be adopted,
wherein places East of the IST longitude have a time
of UTC +6 and those to the West have a time of UTC
+5. This would to a great extent help in the North
Eastern states in maximizing the utilization of daylight
hours and also in Western states during the winter.
Implementation would be difficult as the IST longitude
passes through a region of large population and
shifting clocks by an hour would cause significant
confusion at the border between the two zones. The
trade and travel schedules would have to be
drastically changed. The risk of accidents, especially
rail accidents would drastically increase. Thus this
approach although seemingly power saving, has
The best alternative would be to have a
two Time Zone System using the 90° East
longitude as reference. This proposal is
unlike the permanent shift of IST by 30
minutes. Regions of the country west of
diving 90° East longitude line should
continue to follow the IST system without
any changes. Regions of the country East
to the dividing line should adopt a new
Time Zone 30 minutes ahead of the IST
system i.e. UTC +6.
The 90° East Longitude does not pass through a significant landmass and
also is not a very highly populated region. Thus advancing clocks at
boundary between two Time Zones would not be very difficult to achieve.
North-Eastern states will benefit from advancement in 30 minutes resulting
in maximum utilization of daylight hours thereby reducing need for artificial
lighting. Most North-Eastern states rely solely on Air travel to connect with
the rest of the Country, thus only the Air schedules into and out of the
region would have to be altered. Rail schedules would not be greatly
Adopting such a system would help in encouraging further tapping into the
potential of renewable and alternate sources of energy in the North-Eastern
states particularly hydro-power. Four such generation projects totaling 495MW in
the Kameng basin have been given connectivity recently. A total of 19
generation project developers have applied for connectivity.
It will result in an estimated 11,500 MW reduction in the present supply to the
The Indian carbon emissions can be reduced to levels lower than the estimated
2.3GtCo2 by the year 2050.
Institutional arrangement: Incorporating necessary changes to domestic
sector digital energy meters so as to record consumer demand profile with
respect to time. At the end of month, electricity bill collector recovers this
data through the automated bill machine to generate that month bill.
Tariff Policy: At present, electricity consumers are charged solely based on
units of consumption. New Tariff policy, like Time of Day (TOD) tariff for
industry, could charge customers as per MTZS where high tariff to those
units consumed during maximum sunlight availability.
In order to achieve the desired 1800 KWh annual per capita consumption, India
needs to increase its installed generating capacity as well as adopt innovative
and energy saving policies.
A Multiple Time Zone system would help encourage maximum sunlight utilization
thus reducing consumption of domestic sector which accounts 22% of India net
energy consumption during a year.
With development and investments in solar technologies on the rise, such a
proposal would be highly advantageous.
No major capital investment would be required to implement such a proposal
and it would be beneficial to all stake holders and end consumer in particular.
For an feedback/suggestions/criticism drop me a mail at