Daylight saving time did indeed begin in the United States during World War I, primarily to save fuel by reducing the need to use artificial lighting. Although some states and communities observed daylight saving time between the wars, it was not observed nationally again until World War II.
Short answer: Conception occurs when the egg is released from the ovary at ovulation and meets (is fertilized by) the sperm waiting in the fallopian tube. One sperm burrows into the wall of the egg which signals cells to grow and develop. This is the moment of conception, occurring within about 24 hours of ovulation.
plant fertilization is the joining of male and female gametes, resulting in a zygote. The most generalized form of this process requires four steps: pollination, germination, penetration of the ovule, and fertilization. After fertilization, the zygote divides to form an embryo. Double fertilization is common in angiosperms.