1. I will meet him at 13:00 p.m.
2. I will meet him at 13:00.
3. I will meet him at 1:00 p.m.
(Which ones are correct? Are all correct? Where can I find the information about that on the Internet?)
#3 is correct.
You may also say 1300 hours. You do not need the p.m. following that.
#2 is also correct (you know, after 12 midday, comes 13, 14, etc. for 1pm, 2pm, etc). #1 is not correct as it's redundent since it's understood that theh hour 13 is already 1pm. :o)
Oops I just caught myself in a typo: It's "redundant" not redundent. :o)
Out of the three options you provided, the correct ones are:
1. I will meet him at 1:00 p.m.
2. I will meet him at 13:00.
Both of these options are correct to represent the time as 1:00 p.m. However, option 3 is incorrect because it states "1:00 p.m." as "1:00 p.m. p.m., which is redundant.
If you want to learn more about how to format and express time correctly, you can search for information on websites related to grammar, style guides, or time conventions. Some reliable sources you can refer to include:
1. Grammarly - an online grammar resource (www.grammarly.com)
2. The Chicago Manual of Style - a widely used style guide (www.chicagomanualofstyle.org)
3. The Associated Press Stylebook - a guide often used in journalism (www.apstylebook.com)
4. Oxford Dictionaries - a trusted online dictionary (www.oxforddictionaries.com)
By visiting these websites and searching for specific terms like "how to express time correctly," you can find detailed explanations and guidelines on how to format time accurately.