function clockOfEras;


geoStart = 4550 % mya
geoPresentDay = 0 % mya

clockStart = 2.5;
clockLength = 24;

events = {'precambrianEon' 4550 543 ; 
'hadeanEra' 4550 3800 ; 
'formationOfEarth' 4550 4550; 
'formationOfOceans' 4200 4200;
 'archaenEra' 3800 2500 ;
 'evidenceOfLife' 3850 3850 ;
 'eukaryotes' 2700 2700 ;
 'proterozoicEra' 2500 543 ;
 'algae' 1200 1200 ;
 'softBodiedAnimals' 900 900 ;
 'phanerozoicEon' 543 0 ;
 'paleozoicEra' 543 248 ;
 'cambrianPeriod' 543 490 ;
 'chordates' 530 520 ;
 'cambrianExplosion' 530 520 ;
 'ordovicianPeriod' 490 443 ;
 'landPlants' 480 480 ;
 'fish' 480 480 ;
 'sharks' 450 450 ;
 'silurianPeriod' 443 417 ;
 'vascularLandPlants' 425 425 ;
 'devonianPeriod' 417 354 ;
 'oxygenNear21Percent' 400 400 ;
 'amphibiansOnLand' 375 375 ;
 'gymnospermsEarliestSeedPlantsPollen' 360 360 ;
 '
 }'; 

for eventIdx=1:size(events,2)
  eventName = events{1,eventIdx};
  eventBegin_geo = events{2,eventIdx};
  eventEnd_geo = events{3,eventIdx};

  if eventBegin_geo > geoStart
    continue
  end

  eventName;
  eventBegin_clock = ((geoStart - eventBegin_geo)/geoStart)*clockLength + clockStart;
  eventEnd_clock = ((geoStart - eventEnd_geo)/geoStart)*clockLength + clockStart;

  eventBeginHour = floor(mod(eventBegin_clock, 24));
  eventBeginMinute = mod(eventBegin_clock, 1)*60;
  eventBeginMinuteFloor = floor(eventBeginMinute);


  eventEndHour = floor(mod(eventEnd_clock, 24));
  eventEndMinute = mod(eventEnd_clock, 1)*60;
  eventEndMinuteCeil = ceil(eventEndMinute);

  printf('%20s; %d:%d-%d:%d\n', eventName, eventBeginHour, eventBeginMinuteFloor, eventEndHour, eventEndMinuteCeil);


  

end