<P> Indian Standard Time (IST) is the time observed throughout India and Sri Lanka, with a time offset of UTC + 05: 30 . India does not observe daylight saving time (DSTu) or other seasonal adjustments . In military and aviation time IST is designated E * ("Echo - Star"). </P> <P> Indian Standard Time is calculated on the basis of 82.30' E longitude, in Kakinada, (16 ° 35 ′ N 82 ° 09 ′ E ﻿ / ﻿ 16.58 ° N 82.15 ° E ﻿ / 16.58; 82.15) which is nearly on the corresponding longitude reference line . </P>

Which meridian passing through india is taken as the standard meridian of india and why