@sooty, @gullygossner, I figured out to pass sunset as a starting time to the presence faker node. There are lots of methods for getting the sun times (including getting the current state of sun.sun from HA) but I ended up using the SunPosition subflow, since it gave me morning times as well as evening and goldenHours. After a simple function to extract the time, I put it into a global variable so I can use it in multiple flows. The second step gets the variable and adds text (e.g. {“windowBegin”: “17:27”}) to format it for the subflow’s dynamic configuration. Here is a sample flow:
[{"id":"ca4442d5.fa1d1","type":"subflow","name":"SunPosition","info":"### Sun Position\n\nSet latitude and longitude in the node\n\n### Input\n\nSet the input `msg` (default `msg.payload`)\n\nInject a valid timestamp\n\n","category":"","in":[{"x":92,"y":96,"wires":[{"id":"c3d02a0c.ef5fa8"}]}],"out":[{"x":308,"y":96,"wires":[{"id":"c3d02a0c.ef5fa8","port":0}]}],"env":[{"name":"latitude","type":"num","value":"","ui":{"label":{"en-US":"Latitude"},"type":"input","opts":{"types":["num"]}}},{"name":"longitude","type":"num","value":"","ui":{"label":{"en-US":"Longitude"},"type":"input","opts":{"types":["num"]}}},{"name":"msg","type":"str","value":"payload","ui":{"label":{"en-US":"msg."},"type":"input","opts":{"types":["str"]}}}],"icon":"font-awesome/fa-sun-o"},{"id":"c3d02a0c.ef5fa8","type":"function","z":"ca4442d5.fa1d1","name":"","func":"/*\n (c) 2011-2015, Vladimir Agafonkin\n SunCalc is a JavaScript library for calculating sun/moon position and light phases.\n https://github.com/mourner/suncalc\n*/\n\nvar PI = Math.PI,\n sin = Math.sin,\n cos = Math.cos,\n tan = Math.tan,\n asin = Math.asin,\n atan = Math.atan2,\n acos = Math.acos,\n rad = PI / 180;\n\n// sun calculations are based on http://aa.quae.nl/en/reken/zonpositie.html formulas\n\n\n// date/time constants and conversions\n\nvar dayMs = 1000 * 60 * 60 * 24,\n J1970 = 2440588,\n J2000 = 2451545;\n\nfunction toJulian(date) { return date.valueOf() / dayMs - 0.5 + J1970; }\nfunction fromJulian(j) { return new Date((j + 0.5 - J1970) * dayMs); }\nfunction toDays(date) { return toJulian(date) - J2000; }\n\n\n// general calculations for position\n\nvar e = rad * 23.4397; // obliquity of the Earth\n\nfunction rightAscension(l, b) { return atan(sin(l) * cos(e) - tan(b) * sin(e), cos(l)); }\nfunction declination(l, b) { return asin(sin(b) * cos(e) + cos(b) * sin(e) * sin(l)); }\n\nfunction azimuth(H, phi, dec) { return atan(sin(H), cos(H) * sin(phi) - tan(dec) * cos(phi)); }\nfunction altitude(H, phi, dec) { return asin(sin(phi) * sin(dec) + cos(phi) * cos(dec) * cos(H)); }\n\nfunction siderealTime(d, lw) { return rad * (280.16 + 360.9856235 * d) - lw; }\n\nfunction astroRefraction(h) {\n if (h < 0) // the following formula works for positive altitudes only.\n h = 0; // if h = -0.08901179 a div/0 would occur.\n\n // formula 16.4 of \"Astronomical Algorithms\" 2nd edition by Jean Meeus (Willmann-Bell, Richmond) 1998.\n // 1.02 / tan(h + 10.26 / (h + 5.10)) h in degrees, result in arc minutes -> converted to rad:\n return 0.0002967 / Math.tan(h + 0.00312536 / (h + 0.08901179));\n}\n\n// general sun calculations\n\nfunction solarMeanAnomaly(d) { return rad * (357.5291 + 0.98560028 * d); }\n\nfunction eclipticLongitude(M) {\n\n var C = rad * (1.9148 * sin(M) + 0.02 * sin(2 * M) + 0.0003 * sin(3 * M)), // equation of center\n P = rad * 102.9372; // perihelion of the Earth\n\n return M + C + P + PI;\n}\n\nfunction sunCoords(d) {\n\n var M = solarMeanAnomaly(d),\n L = eclipticLongitude(M);\n\n return {\n dec: declination(L, 0),\n ra: rightAscension(L, 0)\n };\n}\n\n\nvar SunCalc = {};\n\n\n// calculates sun position for a given date and latitude/longitude\n\nSunCalc.getPosition = function (date, lat, lng) {\n\n var lw = rad * -lng,\n phi = rad * lat,\n d = toDays(date),\n\n c = sunCoords(d),\n H = siderealTime(d, lw) - c.ra;\n\n return {\n azimuth: azimuth(H, phi, c.dec),\n altitude: altitude(H, phi, c.dec)\n };\n};\n\n\n// sun times configuration (angle, morning name, evening name)\n\nvar times = SunCalc.times = [\n [-0.833, 'sunrise', 'sunset' ],\n [ -0.3, 'sunriseEnd', 'sunsetStart' ],\n [ -6, 'dawn', 'dusk' ],\n [ -12, 'nauticalDawn', 'nauticalDusk'],\n [ -18, 'nightEnd', 'night' ],\n [ 6, 'goldenHourEnd', 'goldenHour' ]\n];\n\n// adds a custom time to the times config\n\nSunCalc.addTime = function (angle, riseName, setName) {\n times.push([angle, riseName, setName]);\n};\n\n\n// calculations for sun times\n\nvar J0 = 0.0009;\n\nfunction julianCycle(d, lw) { return Math.round(d - J0 - lw / (2 * PI)); }\n\nfunction approxTransit(Ht, lw, n) { return J0 + (Ht + lw) / (2 * PI) + n; }\nfunction solarTransitJ(ds, M, L) { return J2000 + ds + 0.0053 * sin(M) - 0.0069 * sin(2 * L); }\n\nfunction hourAngle(h, phi, d) { return acos((sin(h) - sin(phi) * sin(d)) / (cos(phi) * cos(d))); }\nfunction observerAngle(height) { return -2.076 * Math.sqrt(height) / 60; }\n\n// returns set time for the given sun altitude\nfunction getSetJ(h, lw, phi, dec, n, M, L) {\n\n var w = hourAngle(h, phi, dec),\n a = approxTransit(w, lw, n);\n return solarTransitJ(a, M, L);\n}\n\n\n// calculates sun times for a given date, latitude/longitude, and, optionally,\n// the observer height (in meters) relative to the horizon\n\nSunCalc.getTimes = function (date, lat, lng, height) {\n\n height = height || 0;\n\n var lw = rad * -lng,\n phi = rad * lat,\n\n dh = observerAngle(height),\n\n d = toDays(date),\n n = julianCycle(d, lw),\n ds = approxTransit(0, lw, n),\n\n M = solarMeanAnomaly(ds),\n L = eclipticLongitude(M),\n dec = declination(L, 0),\n\n Jnoon = solarTransitJ(ds, M, L),\n\n i, len, time, h0, Jset, Jrise;\n\n\n var result = {\n solarNoon: fromJulian(Jnoon),\n nadir: fromJulian(Jnoon - 0.5)\n };\n\n for (i = 0, len = times.length; i < len; i += 1) {\n time = times[i];\n h0 = (time[0] + dh) * rad;\n\n Jset = getSetJ(h0, lw, phi, dec, n, M, L);\n Jrise = Jnoon - (Jset - Jnoon);\n\n result[time[1]] = fromJulian(Jrise);\n result[time[2]] = fromJulian(Jset);\n }\n\n return result;\n};\n\n\n// moon calculations, based on http://aa.quae.nl/en/reken/hemelpositie.html formulas\n\nfunction moonCoords(d) { // geocentric ecliptic coordinates of the moon\n\n var L = rad * (218.316 + 13.176396 * d), // ecliptic longitude\n M = rad * (134.963 + 13.064993 * d), // mean anomaly\n F = rad * (93.272 + 13.229350 * d), // mean distance\n\n l = L + rad * 6.289 * sin(M), // longitude\n b = rad * 5.128 * sin(F), // latitude\n dt = 385001 - 20905 * cos(M); // distance to the moon in km\n\n return {\n ra: rightAscension(l, b),\n dec: declination(l, b),\n dist: dt\n };\n}\n\nSunCalc.getMoonPosition = function (date, lat, lng) {\n\n var lw = rad * -lng,\n phi = rad * lat,\n d = toDays(date),\n\n c = moonCoords(d),\n H = siderealTime(d, lw) - c.ra,\n h = altitude(H, phi, c.dec),\n // formula 14.1 of \"Astronomical Algorithms\" 2nd edition by Jean Meeus (Willmann-Bell, Richmond) 1998.\n pa = atan(sin(H), tan(phi) * cos(c.dec) - sin(c.dec) * cos(H));\n\n h = h + astroRefraction(h); // altitude correction for refraction\n\n return {\n azimuth: azimuth(H, phi, c.dec),\n altitude: h,\n distance: c.dist,\n parallacticAngle: pa\n };\n};\n\n\n// calculations for illumination parameters of the moon,\n// based on http://idlastro.gsfc.nasa.gov/ftp/pro/astro/mphase.pro formulas and\n// Chapter 48 of \"Astronomical Algorithms\" 2nd edition by Jean Meeus (Willmann-Bell, Richmond) 1998.\n\nSunCalc.getMoonIllumination = function (date) {\n\n var d = toDays(date || new Date()),\n s = sunCoords(d),\n m = moonCoords(d),\n\n sdist = 149598000, // distance from Earth to Sun in km\n\n phi = acos(sin(s.dec) * sin(m.dec) + cos(s.dec) * cos(m.dec) * cos(s.ra - m.ra)),\n inc = atan(sdist * sin(phi), m.dist - sdist * cos(phi)),\n angle = atan(cos(s.dec) * sin(s.ra - m.ra), sin(s.dec) * cos(m.dec) -\n cos(s.dec) * sin(m.dec) * cos(s.ra - m.ra));\n\n return {\n fraction: (1 + cos(inc)) / 2,\n phase: 0.5 + 0.5 * inc * (angle < 0 ? -1 : 1) / Math.PI,\n angle: angle\n };\n};\n\n\nfunction hoursLater(date, h) {\n return new Date(date.valueOf() + h * dayMs / 24);\n}\n\n// calculations for moon rise/set times are based on http://www.stargazing.net/kepler/moonrise.html article\n\nSunCalc.getMoonTimes = function (date, lat, lng, inUTC) {\n var t = new Date(date);\n if (inUTC) t.setUTCHours(0, 0, 0, 0);\n else t.setHours(0, 0, 0, 0);\n\n var hc = 0.133 * rad,\n h0 = SunCalc.getMoonPosition(t, lat, lng).altitude - hc,\n h1, h2, rise, set, a, b, xe, ye, d, roots, x1, x2, dx;\n\n // go in 2-hour chunks, each time seeing if a 3-point quadratic curve crosses zero (which means rise or set)\n for (var i = 1; i <= 24; i += 2) {\n h1 = SunCalc.getMoonPosition(hoursLater(t, i), lat, lng).altitude - hc;\n h2 = SunCalc.getMoonPosition(hoursLater(t, i + 1), lat, lng).altitude - hc;\n\n a = (h0 + h2) / 2 - h1;\n b = (h2 - h0) / 2;\n xe = -b / (2 * a);\n ye = (a * xe + b) * xe + h1;\n d = b * b - 4 * a * h1;\n roots = 0;\n\n if (d >= 0) {\n dx = Math.sqrt(d) / (Math.abs(a) * 2);\n x1 = xe - dx;\n x2 = xe + dx;\n if (Math.abs(x1) <= 1) roots++;\n if (Math.abs(x2) <= 1) roots++;\n if (x1 < -1) x1 = x2;\n }\n\n if (roots === 1) {\n if (h0 < 0) rise = i + x1;\n else set = i + x1;\n\n } else if (roots === 2) {\n rise = i + (ye < 0 ? x2 : x1);\n set = i + (ye < 0 ? x1 : x2);\n }\n\n if (rise && set) break;\n\n h0 = h2;\n }\n\n var result = {};\n\n if (rise) result.rise = hoursLater(t, rise);\n if (set) result.set = hoursLater(t, set);\n\n if (!rise && !set) result[ye > 0 ? 'alwaysUp' : 'alwaysDown'] = true;\n\n return result;\n};\n\n\n\ninput = env.get(\"msg\")\n\n// get today's sunlight times for London\nvar times = SunCalc.getTimes(msg[input],env.get(\"latitude\"), env.get(\"longitude\"));\n\n// format sunrise time from the Date object\nvar sunriseStr = times.sunrise.getHours() + ':' + times.sunrise.getMinutes();\n\n// get position of the sun (azimuth and altitude) at today's sunrise\nvar sunrisePos = SunCalc.getPosition(times.sunrise, 51.5, -0.1);\n\n// get sunrise azimuth in degrees\nvar sunriseAzimuth = sunrisePos.azimuth * 180 / Math.PI;\n\n\nreturn {payload:{times:times,sunrisePos:sunrisePos,sunriseAzimuth:sunriseAzimuth}}\n","outputs":1,"noerr":0,"x":194,"y":96,"wires":[[]]},{"id":"347d9c0d.faa1e4","type":"tab","label":"Test PF","disabled":false,"info":""},{"id":"5265f842.d8d6e8","type":"inject","z":"347d9c0d.faa1e4","name":"","topic":"","payload":"{\"windowBegin\":\"17:27\"}","payloadType":"json","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":410,"y":220,"wires":[["b4b5c012.cc46a"]]},{"id":"b4b5c012.cc46a","type":"presence-faker","z":"347d9c0d.faa1e4","name":"","onPayload":"on","onPayloadType":"str","onTopic":"","offPayload":"off","offPayloadType":"str","offTopic":"","windowBegin":"21:15","windowEnd":"21:30","minDurationHours":0,"minDurationMinutes":"20","minDurationSeconds":0,"minDuration":"1200","maxDurationHours":0,"maxDurationMinutes":"55","maxDurationSeconds":0,"maxDuration":"3300","minCount":1,"maxCount":"5","startupBehavior":"onStartup","actionOnDisable":"none","x":740,"y":140,"wires":[[]]},{"id":"fb49963b.3870b8","type":"function","z":"347d9c0d.faa1e4","name":"sunset","func":"var time=global.get('sunset')\ntime='{\"windowBegin\": \"' + time + '\"}'\nmsg.payload=time\nreturn msg;","outputs":1,"noerr":0,"x":370,"y":140,"wires":[["1138d166.a5e9ef"]]},{"id":"c494d686.aa1d48","type":"inject","z":"347d9c0d.faa1e4","name":"","topic":"","payload":"","payloadType":"date","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":180,"y":140,"wires":[["fb49963b.3870b8"]]},{"id":"1138d166.a5e9ef","type":"json","z":"347d9c0d.faa1e4","name":"","property":"payload","action":"","pretty":false,"x":550,"y":140,"wires":[["b4b5c012.cc46a"]]},{"id":"bfa941ed.03715","type":"inject","z":"347d9c0d.faa1e4","name":"One AM","topic":"","payload":"","payloadType":"date","repeat":"","crontab":"00 01 * * *","once":false,"onceDelay":"","x":160,"y":60,"wires":[["adf4e158.443bd"]]},{"id":"adf4e158.443bd","type":"subflow:ca4442d5.fa1d1","z":"347d9c0d.faa1e4","name":"","env":[{"name":"latitude","type":"num","value":"40"},{"name":"longitude","type":"num","value":"-100"}],"x":370,"y":60,"wires":[["83cc8f23.9e80a"]]},{"id":"83cc8f23.9e80a","type":"change","z":"347d9c0d.faa1e4","name":"Set to sunset","rules":[{"t":"set","p":"payload","pt":"msg","to":"payload.times.sunset","tot":"msg"}],"action":"","property":"","from":"","to":"","reg":false,"x":570,"y":60,"wires":[["1901046f.59f93c"]]},{"id":"1901046f.59f93c","type":"function","z":"347d9c0d.faa1e4","name":"Parse Time","func":"var test = msg.payload.toString();\ntest = test.substr(16,8)\nmsg.payload = test;\nreturn msg;","outputs":1,"noerr":0,"x":810,"y":60,"wires":[["a944f667.691b98"]]},{"id":"a944f667.691b98","type":"change","z":"347d9c0d.faa1e4","name":"","rules":[{"t":"set","p":"sunset","pt":"global","to":"payload","tot":"msg"}],"action":"","property":"","from":"","to":"","reg":false,"x":1010,"y":60,"wires":[[]]}]