diff -r 2cbf21bb9bdc -r f962f1e5936e www/js/prod_edit.js
--- a/www/js/prod_edit.js	Sun Mar 01 12:48:09 2020 +0100
+++ b/www/js/prod_edit.js	Mon Mar 02 17:15:38 2020 +0100
@@ -300,6 +300,7 @@
    { name: 'starter_type', type: 'int' },
    { name: 'starter_sg', type: 'float' },
    { name: 'starter_viability', type: 'int' },
+   { name: 'yeast_prod_date', type: 'string' },
    { name: 'prop1_type', type: 'int' },
    { name: 'prop1_volume', type: 'float' },
    { name: 'prop2_type', type: 'int' },
@@ -530,6 +531,7 @@
    $('#starter_type').val(dataRecord.starter_type);
    $('#starter_sg').val(dataRecord.starter_sg);
    $('#starter_viability').val(dataRecord.starter_viability);
+   $('#yeast_prod_date').val(dataRecord.yeast_prod_date);
    $('#prop1_type').val(dataRecord.prop1_type);
    $('#prop1_volume').val(dataRecord.prop1_volume);
    $('#prop2_type').val(dataRecord.prop2_type);
@@ -1310,7 +1312,7 @@
 
   $('#yeastGrid').jqxGrid({
    width: 1240,
-   height: 350,
+   height: 325,
    source: yeastAdapter,
    theme: theme,
    selectionmode: 'singlerow',
@@ -1367,6 +1369,7 @@
       row['y_zymocide'] = datarecord.zymocide;
       $('#yeastGrid').jqxGrid('addrow', null, row);
      }
+     calcViability();
      calcYeast();
      $('#yaddrowbutton').jqxDropDownList('clearSelection');
     });
@@ -1383,6 +1386,7 @@
      if (selectedrowindex >= 0 && selectedrowindex < rowscount) {
       id = $('#yeastGrid').jqxGrid('getrowid', selectedrowindex);
       $('#yeastGrid').jqxGrid('deleterow', id);
+      calcViability();
       calcYeast();
      }
     });
@@ -1627,6 +1631,63 @@
  /*
   * Generic functions
   */
+ function calcViability() {
+  var vpm = 1.00;
+  var max = 100;
+  var rowscount = $('#yeastGrid').jqxGrid('getdatainformation').rowscount;
+  if (rowscount) {
+   for (i = 0; i < rowscount; i++) {
+    row = $('#yeastGrid').jqxGrid('getrowdata', i);
+    if (row.y_use == 0) {
+     if (row.y_form == 0) { // Liquid
+      vpm = 0.80;
+      max = 97;
+      if (row.y_laboratory == 'White Labs')
+       vpm = 0.95;
+     } else if (row.y_form == 1) { // dry yeast
+      vpm = 0.98;
+      max = 100;
+     } else if (row.y_form == 6) { // Dried kveik
+      vpm = 1.00;
+      max = 100;
+     } else { // Slant, Culture, Frozen, Bottle
+      vpm = 0.99;
+      max = 97;
+     }
+    }
+   }
+  }
+  var base = max;
+  var days = 0;
+
+  if (parseFloat($('#yeast_prod_date').val()) > 2000) {
+   console.log('calculate viability');
+   var d = new Date();
+   var date2 = $('#yeast_prod_date').val();
+   date2 = date2.split('-');
+   // Now we convert the array to a Date object
+   var date1 = new Date(d.getFullYear(), d.getMonth(), d.getDate());
+   date2 = new Date(date2[0], date2[1] - 1, date2[2]);
+   var diff = parseInt(date1.getTime()) - parseInt(date2.getTime());
+   days = Math.floor(diff/1000/60/60/24);
+
+   var degrade = 1 - ((1 - vpm) / 30.41);  // viability degradation per day.
+   for (i = 0; i < days; i++) {
+    base = base * degrade;
+   }
+   if (base > max) {
+    base = max;
+   }
+   base = Math.round(base);
+  }
+  console.log('age:' + days + ' max:' + max + ' vpm:' + vpm + ' base:' + base);
+
+  if (dataRecord.starter_viability != base) {
+   dataRecord.starter_viability = base;
+   $('#starter_viability').val(dataRecord.starter_viability);
+  }
+ }
+
  function calcSupplies() {
   if (dataRecord.inventory_reduced > 6) {
    $('#ok_pmpt').hide();
@@ -1884,7 +1945,7 @@
     if (row.y_form == 0)
      initcells += (parseFloat(row.y_cells) / 1000000000) * parseFloat(row.y_amount) * (dataRecord.starter_viability / 100);
     else
-     initcells += (parseFloat(row.y_cells) / 1000000) * parseFloat(row.y_amount);
+     initcells += (parseFloat(row.y_cells) / 1000000) * parseFloat(row.y_amount) * (dataRecord.starter_viability / 100);
    }
    // TODO: brett in secondary ??
    if ((((dataRecord.inventory_reduced <= 3) && (row.y_use == 0)) ||  // Primary
@@ -2368,17 +2429,19 @@
    if (row.y_use == 0) { // primary
     // pitchrate see https://www.brewersfriend.com/yeast-pitch-rate-and-starter-calculator/
     // and http://braukaiser.com/blog/blog/2012/11/03/estimating-yeast-growth/
-    pitchrate = 0.75;
-    if (dataRecord.est_og > 1.060)
-     pitchrate = 1.0;
-//  if (dataRecord.est_og > 1.076)
-//   pitchrate = 1.25;       // Wyeast labs. http://www.wyeastlab.com/hb_pitchrates.cfm
-    if (row.y_type == 0) // lager yeast
-     pitchrate *= 2;
-    if (row.y_type == 6) // Kveik
-     pitchrate /= 10; // http://suigenerisbrewing.com/index.php/2019/08/28/drying-kveik-the-grand-finale/
-//   pitchrate = 0.25; // Who knows.
-
+    if (row.y_type == 0) { // lager yeast
+     pitchrate = 1.5;
+     if (dataRecord.est_og > 1.060)
+      pitchrate = 2.0;
+    } else if (row.y_type == 6) { // Kveik
+     pitchrate = 0.075;
+    } else {
+     pitchrate = 0.75;
+     if (dataRecord.est_og > 1.060)
+      pitchrate = 1.0;
+     if (dataRecord.est_og > 1.076)
+      pitchrate = 1.25; // Wyeast labs. http://www.wyeastlab.com/hb_pitchrates.cfm
+    }
 //    if (row.y_form == 1) { // dry yeast
 //    } else { // possible starter needed
 //    }
@@ -3558,7 +3621,7 @@
    $('#starter_type').jqxDropDownList({ disabled: true });
    $('#starter_try').jqxButton({ disabled: true });
    $('#starter_sg').jqxNumberInput({ spinButtons: false, readOnly: true, width: 90 });
-   $('#starter_viability').jqxNumberInput({ spinButtons: false, readOnly: true, width: 90 });
+   $('#yeast_prod_date').jqxDateTimeInput({ disabled: true });
   }
   if (dataRecord.stage > 3) { // Primary fermentation done
    $('#brew_date_start').jqxDateTimeInput({ disabled: true });
@@ -3652,13 +3715,11 @@
    $('#starter_type').jqxDropDownList({ disabled: false });
    $('#starter_try').jqxButton({ disabled: false });
    $('#starter_sg').jqxNumberInput({ spinButtons: true, readOnly: false, width: 110 });
-   $('#starter_viability').jqxNumberInput({ spinButtons: true, readOnly: false, width: 110 });
   } else {
    $('#propagator').hide();
    $('#starter_type').jqxDropDownList({ disabled: true });
    $('#starter_try').jqxButton({ disabled: true });
    $('#starter_sg').jqxNumberInput({ spinButtons: false, readOnly: true, width: 90 });
-   $('#starter_viability').jqxNumberInput({ spinButtons: false, readOnly: true, width: 90 });
   }
  }
 
@@ -3698,13 +3759,6 @@
     calcYeast();
    }
   });
-  $('#starter_viability').on('change', function(event) {
-   if (event.args) {
-    dataRecord.starter_viability = event.args.value;
-    calcFermentables();
-    calcYeast();
-   }
-  });
   $('#prop1_type').on('change', function(event) {
    if (event.args) {
     dataRecord.prop1_type = event.args.index;
@@ -4436,6 +4490,7 @@
    starter_type: $('#starter_type').val(),
    starter_sg: parseFloat($('#starter_sg').jqxNumberInput('decimal')),
    starter_viability: parseFloat($('#starter_viability').jqxNumberInput('decimal')),
+   yeast_prod_date: $('#yeast_prod_date').val(),
    prop1_type: $('#prop1_type').val(),
    prop1_volume: parseFloat($('#prop1_volume').jqxNumberInput('decimal')),
    prop2_type: $('#prop2_type').val(),
@@ -5224,6 +5279,13 @@
  $('#need_cells').jqxNumberInput(Show1dec);
  $('#plato_cells').jqxTooltip({ content: 'De berekende hoeveelheid gistcellen in miljard per ml per graad Plato. Dit is de zogenaamde pitchrate.' });
  $('#plato_cells').jqxNumberInput(Show2dec);
+ $('#yeast_prod_date').jqxTooltip({ content: 'Bij korrelgisten is meestal "best voor" datum op het zakje gedrukt.<br>Gebruik die datum maar dan twee jaar eerder als productie datum.<br>Bij White Labs is de productie datum vier maanden voor de "Best by" datum die geprint op het buisje.<br>Bij Wyeast is dit de "manufacture date" die op het pak geprint is.<br>Voor schuine buis, slurry, opkweek en gedroogd is dit de datum dat je de gist geoogst hebt.' });
+ $('#yeast_prod_date').jqxDateTimeInput(Dateopts);
+ $('#yeast_prod_date').on('close', function(event) {
+  calcViability();
+  calcFermentables();
+  calcYeast();
+ });
  $('#popupYeast').jqxWindow({
   width: 800,
   height: 300,
@@ -5265,6 +5327,7 @@
    y_avail: yeastData.y_avail
   };
   $('#yeastGrid').jqxGrid('updaterow', rowID, row);
+  calcViability();
   calcFermentables();
   calcYeast();
  });
@@ -5321,6 +5384,7 @@
    } else {
     $('#wy_pmpt_amount').html('Volume ml:');
    }
+   calcViability();
    calcFermentables();
    calcYeast();
   }
@@ -5348,6 +5412,7 @@
   if (event.args) {
    var index = event.args.index;
    yeastData.y_use = index;
+   calcViability();
    calcFermentables();
    calcYeast();
   }
@@ -5389,12 +5454,11 @@
  });
  $('#starter_sg').jqxTooltip({ content: 'Het ideale starter SG moet tussen de 1.030 en 1.040 zijn. Optimaal is 1.037.' });
  $('#starter_sg').jqxNumberInput(SGopts);
- $('#starter_viability').jqxTooltip({
-  content: 'De gist conditie te berekenen vanaf de productie datum. Vloeibare gist verlist iedere maand ongeveer 20% active cellen.'
- });
- $('#starter_viability').jqxNumberInput(Perc0);
+ $('#starter_viability').jqxTooltip({ content: 'De gist conditie.' });
+ $('#starter_viability').jqxNumberInput(Smal0dec);
  $('#starter_try').jqxButton({ template: 'primary', width: '100px', height: 23, theme: theme });
 
+
  // Tab 7, Mashing
  $('#mash_name').jqxTooltip({ content: 'De omschrijving van dit maisch profiel.' });
  $('#mash_name').jqxInput({ theme: theme, width: 320, height: 23 });