The use of the present continuous and present perfect with time expressions such as today, this week, this year, etc. depends on whether the time period is considered as ongoing or finished at the time of speaking.
Present continuous:
We use the present continuous (am/are/is + verb-ing) with time expressions like today, this week, this year when we refer to actions or situations happening around now or during the specified time period.
Examples:
- You're working hard today. (referring to the ongoing action of working hard today)
- The company I work for isn't doing so well this year. (referring to the ongoing performance of the company throughout the year)
Present perfect:
We use the present perfect (have/has + past participle) with time expressions like today, this evening, this year when the time period is not yet finished at the time of speaking.
Examples:
- I've drunk four cups of coffee today. (referring to the actions of drinking coffee earlier in the day, which are still relevant at the time of speaking)
- Have you had a holiday this year? (referring to the time period of the year, which is not yet finished)
In summary, the present continuous is used for ongoing actions or situations around now or during the specified time period, while the present perfect is used for actions or situations that happened at some point in the specified time period and are still relevant at the time of speaking.