Here you can find the source of toSeconds(final Duration time)
public static double toSeconds(final Duration time)
//package com.java2s; /*-//from ww w . j a v a2 s . c o m * #%L * The MIT License (MIT) * %% * Copyright (C) 2016 - 2018 Vinz (https://github.com/gv2011) * %% * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. * #L% */ import java.time.Duration; import java.time.temporal.ChronoUnit; public class Main { private static final double NANOS_PER_SECOND = ChronoUnit.SECONDS.getDuration().toNanos(); public static double toSeconds(final Duration time) { double result = time.getSeconds(); result += ((double) time.getNano()) / NANOS_PER_SECOND; return result; } }