வார்ப்புரு:Period start
&lt;includeonly&gt;{{#expr:{{#switch: {{Period id|{{{1|{{PAGENAME}}}}}}}
 
 &lt;!-- Some other notable dates --&gt;
 
 |burgess shale|middle middle cambrian&lt;!--Middle middle is approximate; cf. Burgess Shale--&gt;=508
 |chengjiang=520
 |sirius passet=518
 |doushantou=570
 
 &lt;!-- Data from ICS chart
 
 | Supereon
 |   Eon
 |     Era
 |       Period
 |         Epoch/Series
 |           Age/Stage
 |             other division (other sources - not in ICS chart)
 The names from the ICS chart are always first on the line.
 --&gt;
 | முன் கேம்பிரியன்
 |   hadean              = 4600
 |   archean
 |     eoarchean | isuan = 4000
 |     paleoarchean      = 3600
 |     mesoarchean       = 3200
 |     neoarchean        = 2800
 |   proterozoic
 |     paleoproterozoic
 |       siderian        = 2500
 |       rhyacian        = 2300
 |       orosirian       = 2050
 |       statherian      = 1800
 |     mesoproterozoic
 |       calymmian       = 1600
 |       ectasian | riphean
                         = 1400
 |       stenian         = 1200
 |             mayanian  = 1100
 |             sinian | sturtian
                         = 1050
 |     neoproterozoic
 |       tonian          = 1000
 |             baikalian = 850 
 |       cryogenian      = 720
 |       ediacaran | vendian
                         = 635
   &lt;!-- end of precambrian --&gt;
 |   phanerozoic
 |     paleozoic
 |       கேம்பிரியக் காலம்
 |        lower cambrian &lt;!-- group of two epochs, not in ICS chart --&gt;
 |         terreneuvian | lowest cambrian | earliest cambrian
 |           fortunian
 |             manykaian | nemakit daldynian
                          = 541.0
 |             caerfai | tommotian
                          = 530
 |           cambrian stage 2
                          = 529
 |         cambrian series 2
 |           cambrian stage 3 | middle lower cambrian
 |             atdabanian = 521
 |             botomian   = 522
 |             toyonian | upper lower cambrian
                          = 516
 |           cambrian stage 4
                          = 514
          &lt;!-- end of lower cambrian --&gt;
 |         cambrian series 3 | middle cambrian
 |           cambrian stage 5 | lower middle cambrian | st davids
                          = 509
 |           drumian      = 504.5
 |           guzhangian | nganasanian | mindyallan
                          = 500.5
 |         furongian | upper cambrian | merioneth
 |           paibian | franconian&lt;!--unofficial and approximate!--&gt;
                          = 497
 |           jiangshanian = 494
 |             upper upper cambrian | mansian
                          = 490&lt;!--Arbritary number.--&gt;
 |           cambrian stage 10     = 489.5
 |       ஓர்டோவிசியக் காலம்
 |         lower ordovician
 |           tremadocian  = 485.4
 |             upper lower ordovician
                          = 479
 |           floian | arenig
                          = 477.7
 |         middle ordovician
 |           dapingian | ordovician iii | lower middle ordovician
                          = 470.0
 |           darriwilian  = 467.3
 |         upper ordovician
 |           sandbian | ordovician v | lower upper ordovician
                          = 458.4
 |             middle upper ordovician
                          = 455
 |           katian | ordovician vi
                          = 453.0
 |           hirnantian   = 445.2
 |       சிலுரியக் காலம்
 |         llandovery | lower silurian
 |           rhuddanian   = 443.8
 |           aeronian     = 440.8
 |           telychian    = 438.5
 |         wenlock
 |           sheinwoodian = 433.4
 |           homerian     = 430.5
 |         ludlow | upper silurian
 |           gorstian     = 427.4
 |           ludfordian   = 425.6
 |         pridoli
 |           unnamed pridoli stage
                          = 423.0
 |       டெவோனியக் காலம்
 |         lower devonian
 |           lochkovian | downtonian&lt;!--approx--&gt;
                          = 419.2
 |           pragian | praghian
                          = 410.8
 |           emsian       = 407.6
 |         middle devonian
 |           eifelian     = 393.3
 |           givetian     = 387.7
 |         upper devonian
 |           frasnian     = 382.7
 |           famennian    = 372.2
 |       கார்பனிபெரசுக் காலம்
 |        mississippian | lower carboniferous &lt;!-- Subperiod from ICS chart --&gt;
 |         lower mississippian
 |           tournaisian  = 358.9
 |         middle mississippian
 |           visean       = 346.7
 |         upper mississippian
 |           serpukhovian = 330.9
 |             namurian   = 326
 |        pennsylvanian | upper carboniferous &lt;!-- Subperiod from ICS chart --&gt;
 |         lower pennsylvanian
 |           bashkirian   = 323.2
 |             westphalian= 313
 |         middle pennsylvanian
 |           moscovian    = 315.2
 |         upper pennsylvanian
 |           kasimovian   = 307.0
 |             stephanian = 304
 |           gzhelian     = 303.7
 |       பேர்மியன் காலம்
 |         cisuralian | lower permian
 |           asselian     = 298.9
 |           sakmarian    = 295.0
 |           artinskian   = 290.1
 |           kungurian    = 283.5
 |         guadalupian | middle permian
 |           roadian | ufimian
                          = 272.3
 |           wordian      = 268.8
 |           capitanian   = 265.1
 |         lopingian | upper permian
 |           wuchiapingian | longtanian
                          = 259.8
 |           changhsingian= 254.14
 |     mesozoic
 |       டிராசிக் காலம்
 |         lower triassic
 |           induan       = 252.17
 |           olenekian | spathian
                          = 251.2
 |         middle triassic 
 |           anisian      = 247.2
 |           ladinian     = 242
 |         upper triassic
 |           carnian      = 237
 |           norian       = 227
 |           rhaetian     = 208.5
 |       சுராசிக் காலம்
 |         lower jurassic
 |           hettangian   = 201.3
 |           sinemurian   = 199.3
 |           pliensbachian= 190.8
 |           toarcian     = 182.7
 |         middle jurassic
 |           aalenian     = 174.1
 |           bajocian     = 170.3
 |           bathonian    = 168.3
 |           callovian    = 166.1
 |         upper jurassic
 |           oxfordian    = 163.5
 |           kimmeridgian = 157.3
 |           tithonian    = 152.1
 |       கிரீத்தேசியக் காலம்
 |         lower cretaceous
 |           berriasian | neocomian
                          = 145.0
 |           valanginian  = 139.8
 |           hauterivian  = 132.9
 |           barremian | gallic
                          = 129.4
 |           aptian       = 125.0
 |           albian       = 113.0
 |         upper cretaceous
 |           cenomanian   = 100.5
 |           turonian     = 93.9
 |           coniacian | senonian
                          = 89.8
 |           santonian    = 86.3
 |           campanian    = 83.6
 |           maastrichtian= 72.1
 |     cenozoic
 |      tertiary &lt;!-- Group of 2 periods, former term --&gt;
 |       பாலியோயின் காலம்
 |         paleocene
 |           danian | lower paleocene
                          = 66.0
 |             puercan    = 65
 |             torrejonian= 63.3
 |           selandian | middle paleocene
                          = 61.6
 |             tiffanian  = 60.2
 |           thanetian | upper paleocene
                          = 59.2
 |             clarkforkian
                          = 56.8
 |         eocene
 |           ypresian | lower eocene | mp 10
                          = 56.0
 |             wasatchian = 55.4
 |             bridgerian = 50.3
 |          middle eocene &lt;!-- Group of two stages, not in ICS chart --&gt;
 |           lutetian | mp 11
                          = 47.8
 |             uintan     = 46.2
 |             duchesnean = 42
 |           bartonian    = 41.2
 |             chadronian = 38
            &lt;!-- end of middle eocene --&gt;
 |           priabonian | upper eocene
                          = 37.8
 |         oligocene
 |           rupelian | lower oligocene
 |             orellan    = 33.9
 |             whitneyan  = 33.3
 |             arikeean   = 30.6
 |           chattian | upper oligocene
                          = 28.1
 |       நியோயின் காலம்
 |         miocene
 |          lower miocene &lt;!-- Group of 2 stages, not in ICS chart --&gt;
 |           aquitanian   = 23.03
 |             hemingfordian
                          = 20.6
 |           burdigalian  = 20.44
 |             barstovian = 16.3
 |          middle miocene &lt;!-- Group of 2 stages, not in ICS chart --&gt;
 |           langhian     = 15.97
 |           serravallian = 13.82
 |             clarendonian
                          = 13.6
 |          upper miocene &lt;!-- Group of 2 stages, not in ICS chart --&gt;
 |           tortonian    = 11.63
 |             hemphillian= 10.3
 |           messinian    = 7.246
 |         pliocene
 |           zanclean | lower pliocene
                          = 5.333
 |             blancan    = 4.75
 |           piacenzian | upper pliocene
                          = 3.600
        &lt;!-- end of tertiary --&gt;
 |       quaternary
 |         pleistocene
 |          lower pleistocene &lt;!-- Group of 2 stages, implied from ICS chart --&gt;
 |           gelasian     = 2.58
 |           calabrian    = 1.80
 |             irvingtonian
                          = 1.8
            &lt;!-- end of lower pleistocene --&gt;
 |           middle pleistocene
                          = 0.781
 |             rancholabrean
                          = 0.24
 |           upper pleistocene
                          = 0.126
 |         holocene       = 0.0117
 | now | recent | present | current
                          = 0