No, you cannot say "19 o'clock" in natural English speech; it sounds very unnatural and incorrect because the "o'clock" suffix is used with the 12-hour clock (e.g., "seven o'clock"), while 19:00 (7 PM) is from the 24-hour format, which is spoken as "seven p.m.," "seven in the evening," or sometimes "nineteen hundred hours" (in military/formal contexts).
We only use 'o'clock' when we are telling time using the 12-hour clock so English speakers would never say '13 o'clock'.
Eight thirty (simple). Half past eight (neither simple nor clumsy). Thirty minutes past eight (clumsy).
In addition, when writing the times 1:00 pm, 2:00 pm, etc., it is perfectly acceptable to omit the zeroes and write 1 pm, 2 pm, instead. Finally, note that while in the US we use a 12-hour clock, some countries use a 24-hour clock, or military time.
Saying the time with minutes
If it's not on the hour, we include the minutes. For example, 3:15 is said as “three fifteen,” and 3:30 is “three thirty.” You can also say the minutes first, like “fifteen minutes past three” or “half past three” for 3:30. Past is used for times up to 30 minutes after the hour.
19 hours is 1140 minutes. Time conversion involves understanding the relationship between hours and minutes. Since 1 hour is equivalent to 60 minutes, converting hours to minutes is a straightforward multiplication process.
The minutes, however, remain the same. Therefore, 19:30 becomes 7:30 PM. This is because 19:30 is in the second half of the day, so it is represented in the PM time. Therefore, 19:30 on a 24-hour clock is equivalent to 7:30 PM on a 12-hour clock.
The hour after midnight is a.m., which means you can write that time as 12:00 a.m. If you're using a 24-hour clock, digital clock, or military time, 12:00 is noon or midday. Military time also refers to noon as 12:00 p.m. You don't need to add p.m. to 12:00 because 12:00 military time will always be noon.
Evening takes place between the hours of 6pm - 9pm. It lasts from the time the sun sets, and can be marked by twilight or dusk.
The times provided by these two bodies do not always concur with those provided by a clock. Hence there was a need to differentiate between the time provided "of the clock" (o'clock) and the time used by the vast majority of people in a given locality.
Military time is always written as four digits (hours and minutes) without a colon. For instance, 9:00 a.m. would be written as 0900. If the time is past noon, you simply continue adding hours instead of restarting at 12:00. For example, 3:12 p.m. would be written as 1512.
07:30 p.m. in 24-hour format is 19:30. The 24-hour format, by contrast, runs continuously from 00:00 (midnight) to 23:59, eliminating the need for AM/PM.
While you might hear "nineteen hundred hours" in a military context, in normal English you can only say "seven o'clock". If you want to make it clear which "seven o'clock" you mean, you can add "...in the evening" or alternatively say "seven p.m.".
If it's 6 hours after midnight, it's 6 a.m. in a.m./p.m. time and 0600 (or "oh-six hundred") in military time. If it's 7 hours after noon, it's 7 p.m. in a.m./p.m. time and 1900 (or "nineteen hundred") in military time.
Yes, 2130 in 24-hour (or military) time is 9:30 PM in standard 12-hour time, with the "30" representing the minutes past the hour, and the "21" indicating the 9th hour after noon (since 12 PM + 9 hours = 9 PM).
It is a guater past nine = It is fifteen past nine ( 09:15 )
The time can be written in a variety of ways to fit your style and theme. For example, if your wedding is at 5:30 p.m. the traditional wording to use is "half after five o'clock" or "five-thirty in the evening." If this is too formal for your style, you may write the time simply as 5:30 p.m.
If we wanted to tell someone the time as we saw it on this new clock invention we would say it's three of the clock as opposed to three of the sundial or three of the candle. Sometime around the sixteenth or seventeenth centuries, that got shortened to three o'clock.